diff --git a/BUILD b/BUILD.bazel
similarity index 99%
rename from BUILD
rename to BUILD.bazel
index aaff71a0c..335261439 100644
--- a/BUILD
+++ b/BUILD.bazel
@@ -1496,7 +1496,7 @@ pkg_files(
         "protobuf*.pc.in",
         "test-driver",
     ], allow_empty = True) + [
-        "BUILD",
+        "BUILD.bazel",
         "CHANGES.txt",
         "CMakeLists.txt",
         "CONTRIBUTORS.txt",
@@ -1512,7 +1512,7 @@ pkg_files(
         "maven_install.json",
         "update_file_lists.sh",
         "//third_party:zlib.BUILD",
-        "//util/python:BUILD",
+        "//util/python:BUILD.bazel",
     ],
     strip_prefix = strip_prefix.from_root(""),
     visibility = ["//pkg:__pkg__"],
diff --git a/Makefile.am b/Makefile.am
index 6c1bf316c..748099950 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -11,7 +11,7 @@ SUBDIRS = . src
 # Always include third_party directories in distributions.
 #
 # Note that distribution artifacts will be produced by Bazel in the future.
-# See pkg/BUILD for overall definitions.
+# See pkg/BUILD.bazel for overall definitions.
 DIST_SUBDIRS = src conformance benchmarks third_party/googletest
 
 # Build gmock before we build protobuf tests.  We don't add gmock to SUBDIRS
@@ -51,7 +51,7 @@ clean-local:
 pkgconfigdir = $(libdir)/pkgconfig
 pkgconfig_DATA = protobuf.pc protobuf-lite.pc
 
-# Note: please keep this in sync with the dist_files rule in csharp/BUILD.
+# Note: please keep this in sync with the dist_files rule in csharp/BUILD.bazel.
 csharp_EXTRA_DIST=                                                           \
   global.json                                                                \
   csharp/.editorconfig                                                       \
@@ -283,11 +283,11 @@ csharp_EXTRA_DIST=                                                           \
   csharp/src/Google.Protobuf/UnknownFieldSet.cs                              \
   csharp/src/Google.Protobuf/UnsafeByteOperations.cs
 
-# Note: please keep this in sync with the dist_files rules under java/.../BUILD.
+# Note: please keep this in sync with the dist_files rules under java/.../BUILD.bazel.
 java_EXTRA_DIST=                                                                   \
   java/README.md                                                                   \
   java/bom/pom.xml                                                                 \
-  java/core/BUILD                                                                  \
+  java/core/BUILD.bazel                                                            \
   java/core/generate-sources-build.xml                                             \
   java/core/generate-test-sources-build.xml                                        \
   java/core/pom.xml                                                                \
@@ -543,9 +543,9 @@ java_EXTRA_DIST=
   java/core/src/test/proto/com/google/protobuf/test_check_utf8_size.proto          \
   java/core/src/test/proto/com/google/protobuf/test_custom_options.proto           \
   java/core/src/test/proto/com/google/protobuf/wrappers_test.proto                 \
-  java/internal/BUILD                                                              \
+  java/internal/BUILD.bazel                                                        \
   java/internal/testing.bzl                                                        \
-  java/kotlin/BUILD                                                                \
+  java/kotlin/BUILD.bazel                                                          \
   java/kotlin/generate-sources-build.xml                                           \
   java/kotlin/generate-test-sources-build.xml                                      \
   java/kotlin/pom.xml                                                              \
@@ -572,7 +572,7 @@ java_EXTRA_DIST=
   java/kotlin/src/test/proto/com/google/protobuf/evil_names_proto3.proto           \
   java/kotlin/src/test/proto/com/google/protobuf/example_extensible_message.proto  \
   java/kotlin/src/test/proto/com/google/protobuf/multiple_files_proto3.proto       \
-  java/kotlin-lite/BUILD                                                           \
+  java/kotlin-lite/BUILD.bazel                                                     \
   java/kotlin-lite/generate-sources-build.xml                                      \
   java/kotlin-lite/generate-test-sources-build.xml                                 \
   java/kotlin-lite/lite.awk                                                        \
@@ -583,7 +583,7 @@ java_EXTRA_DIST=
   java/kotlin-lite/src/test/kotlin/com/google/protobuf/ExtendableMessageLiteExtensionsTest.kt\
   java/kotlin-lite/src/test/kotlin/com/google/protobuf/Proto2LiteTest.kt           \
   java/lite.md                                                                     \
-  java/lite/BUILD                                                                  \
+  java/lite/BUILD.bazel                                                            \
   java/lite/generate-sources-build.xml                                             \
   java/lite/generate-test-sources-build.xml                                        \
   java/lite/lite.awk                                                               \
@@ -591,9 +591,9 @@ java_EXTRA_DIST=
   java/lite/pom_template.xml                                                       \
   java/lite/process-lite-sources-build.xml                                         \
   java/lite/src/test/java/com/google/protobuf/LiteTest.java                        \
-  java/BUILD                                                                       \
+  java/BUILD.bazel                                                                 \
   java/pom.xml                                                                     \
-  java/util/BUILD                                                                  \
+  java/util/BUILD.bazel                                                            \
   java/util/pom.xml                                                                \
   java/util/pom_template.xml                                                       \
   java/util/src/main/java/com/google/protobuf/util/Durations.java                  \
@@ -612,10 +612,10 @@ java_EXTRA_DIST=
   java/util/src/test/java/com/google/protobuf/util/ValuesTest.java                 \
   java/util/src/test/proto/com/google/protobuf/util/json_test.proto
 
-# Note: please keep this in sync with the dist_files rule in objectivec/BUILD.
+# Note: please keep this in sync with the dist_files rule in objectivec/BUILD.bazel.
 objectivec_EXTRA_DIST=                                                       \
   objectivec/.clang-format                                                   \
-  objectivec/BUILD                                                           \
+  objectivec/BUILD.bazel                                                     \
   objectivec/DevTools/check_version_stamps.sh                                \
   objectivec/DevTools/compile_testing_protos.sh                              \
   objectivec/DevTools/full_mac_build.sh                                      \
@@ -821,7 +821,7 @@ objectivec_EXTRA_DIST=                                                       \
   objectivec/Tests/UnitTests-Info.plist                                       \
   Protobuf.podspec
 
-# Note: please keep this in sync with the dist_files rule in php/BUILD.
+# Note: please keep this in sync with the dist_files rule in php/BUILD.bazel.
 php_EXTRA_DIST=                                                       \
   php/README.md                                                       \
   php/REFCOUNTING.md                                                  \
@@ -1018,7 +1018,7 @@ php_EXTRA_DIST=                                                       \
   php/tests/WellKnownTest.php                                         \
   php/tests/WrapperTypeSettersTest.php
 
-# Note: please keep this in sync with the python_dist_files rule in BUILD.
+# Note: please keep this in sync with the python_dist_files rule in BUILD.bazel.
 python_EXTRA_DIST=                                                           \
   python/MANIFEST.in                                                         \
   python/google/__init__.py                                                  \
@@ -1142,7 +1142,7 @@ python_EXTRA_DIST=                                                           \
   python/tox.ini                                                             \
   python/README.md
 
-# Note: please keep this in sync with the dist_files rule in ruby/BUILD.
+# Note: please keep this in sync with the dist_files rule in ruby/BUILD.bazel.
 ruby_EXTRA_DIST=                                                             \
   ruby/Gemfile                                                               \
   ruby/.gitignore                                                            \
@@ -1220,7 +1220,7 @@ ruby_EXTRA_DIST=                                                             \
 
 all_EXTRA_DIST=$(csharp_EXTRA_DIST) $(java_EXTRA_DIST) $(objectivec_EXTRA_DIST) $(php_EXTRA_DIST) $(python_EXTRA_DIST) $(ruby_EXTRA_DIST)
 
-# Note: please keep this in sync with the common_dist_files rule in BUILD.
+# Note: please keep this in sync with the common_dist_files rule in BUILD.bazel.
 EXTRA_DIST = $(@DIST_LANG@_EXTRA_DIST)              \
   autogen.sh                                        \
   generate_descriptor_proto.sh                      \
@@ -1229,7 +1229,7 @@ EXTRA_DIST = $(@DIST_LANG@_EXTRA_DIST)              \
   CONTRIBUTORS.txt                                  \
   CHANGES.txt                                       \
   update_file_lists.sh                              \
-  BUILD                                             \
+  BUILD.bazel                                       \
   WORKSPACE                                         \
   CMakeLists.txt                                    \
   cmake/abseil-cpp.cmake                            \
@@ -1254,12 +1254,12 @@ EXTRA_DIST = $(@DIST_LANG@_EXTRA_DIST)              \
   compiler_config_setting.bzl                       \
   build_files_updated_unittest.sh                   \
   cc_proto_blacklist_test.bzl                       \
-  csharp/BUILD                                      \
+  csharp/BUILD.bazel                                \
   editors/README.txt                                \
   editors/proto.vim                                 \
   editors/protobuf-mode.el                          \
   examples/AddPerson.java                           \
-  examples/BUILD                                    \
+  examples/BUILD.bazel                              \
   examples/CMakeLists.txt                           \
   examples/ListPeople.java                          \
   examples/Makefile                                 \
@@ -1281,14 +1281,14 @@ EXTRA_DIST = $(@DIST_LANG@_EXTRA_DIST)              \
   examples/pubspec.yaml                             \
   internal.bzl                                      \
   maven_install.json                                \
-  php/BUILD                                         \
+  php/BUILD.bazel                                   \
   protobuf.bzl                                      \
   protobuf_deps.bzl                                 \
   protobuf_release.bzl                              \
   protobuf_version.bzl                              \
-  ruby/BUILD                                        \
+  ruby/BUILD.bazel                                  \
   third_party/zlib.BUILD                            \
-  util/python/BUILD
+  util/python/BUILD.bazel
 
 # Deletes all the files generated by autogen.sh.
 MAINTAINERCLEANFILES =   \
diff --git a/benchmarks/BUILD b/benchmarks/BUILD.bazel
similarity index 98%
rename from benchmarks/BUILD
rename to benchmarks/BUILD.bazel
index 2f7b4c749..83b2c7ee5 100644
--- a/benchmarks/BUILD
+++ b/benchmarks/BUILD.bazel
@@ -75,7 +75,7 @@ pkg_files(
         ],
         exclude = [
             "__init__.py",  # not in autotools dist
-            "BUILD",
+            "BUILD.bazel",
             "go/*",
         ],
     ),
diff --git a/benchmarks/cpp/BUILD b/benchmarks/cpp/BUILD.bazel
similarity index 100%
rename from benchmarks/cpp/BUILD
rename to benchmarks/cpp/BUILD.bazel
diff --git a/benchmarks/datasets/BUILD b/benchmarks/datasets/BUILD.bazel
similarity index 98%
rename from benchmarks/datasets/BUILD
rename to benchmarks/datasets/BUILD.bazel
index 1cb11bdda..2a8b40266 100644
--- a/benchmarks/datasets/BUILD
+++ b/benchmarks/datasets/BUILD.bazel
@@ -61,7 +61,7 @@ java_library(
 
 pkg_files(
     name = "dist_files",
-    srcs = ["BUILD"],
+    srcs = ["BUILD.bazel"],
     strip_prefix = strip_prefix.from_root(""),
     visibility = ["//benchmarks:__pkg__"],
 )
diff --git a/benchmarks/datasets/google_message1/proto2/BUILD b/benchmarks/datasets/google_message1/proto2/BUILD.bazel
similarity index 100%
rename from benchmarks/datasets/google_message1/proto2/BUILD
rename to benchmarks/datasets/google_message1/proto2/BUILD.bazel
diff --git a/benchmarks/datasets/google_message1/proto3/BUILD b/benchmarks/datasets/google_message1/proto3/BUILD.bazel
similarity index 100%
rename from benchmarks/datasets/google_message1/proto3/BUILD
rename to benchmarks/datasets/google_message1/proto3/BUILD.bazel
diff --git a/benchmarks/datasets/google_message2/BUILD b/benchmarks/datasets/google_message2/BUILD.bazel
similarity index 100%
rename from benchmarks/datasets/google_message2/BUILD
rename to benchmarks/datasets/google_message2/BUILD.bazel
diff --git a/benchmarks/datasets/google_message3/BUILD b/benchmarks/datasets/google_message3/BUILD.bazel
similarity index 100%
rename from benchmarks/datasets/google_message3/BUILD
rename to benchmarks/datasets/google_message3/BUILD.bazel
diff --git a/benchmarks/datasets/google_message4/BUILD b/benchmarks/datasets/google_message4/BUILD.bazel
similarity index 100%
rename from benchmarks/datasets/google_message4/BUILD
rename to benchmarks/datasets/google_message4/BUILD.bazel
diff --git a/csharp/BUILD b/csharp/BUILD.bazel
similarity index 97%
rename from csharp/BUILD
rename to csharp/BUILD.bazel
index 6d31ba0cc..2c150841b 100644
--- a/csharp/BUILD
+++ b/csharp/BUILD.bazel
@@ -13,7 +13,7 @@ pkg_files(
     ]) + [
         ".editorconfig",
         ".gitignore",
-        "BUILD",
+        "BUILD.bazel",
         "CHANGES.txt",
         "Google.Protobuf.Tools.nuspec",
         "Google.Protobuf.Tools.targets",
diff --git a/examples/BUILD b/examples/BUILD.bazel
similarity index 99%
rename from examples/BUILD
rename to examples/BUILD.bazel
index 358a1529b..d5a719ca8 100644
--- a/examples/BUILD
+++ b/examples/BUILD.bazel
@@ -110,7 +110,7 @@ pkg_files(
     name = "dist_files",
     srcs = [
         "AddPerson.java",
-        "BUILD",
+        "BUILD.bazel",
         "CMakeLists.txt",
         "ListPeople.java",
         "Makefile",
diff --git a/java/BUILD b/java/BUILD.bazel
similarity index 98%
rename from java/BUILD
rename to java/BUILD.bazel
index c084db639..b3178c9f8 100644
--- a/java/BUILD
+++ b/java/BUILD.bazel
@@ -28,7 +28,7 @@ filegroup(
 pkg_files(
     name = "dist_files",
     srcs = [
-        "BUILD",
+        "BUILD.bazel",
         "README.md",
         "bom/pom.xml",
         "lite.md",
diff --git a/java/core/BUILD b/java/core/BUILD.bazel
similarity index 99%
rename from java/core/BUILD
rename to java/core/BUILD.bazel
index 685ebd098..4a3884768 100644
--- a/java/core/BUILD
+++ b/java/core/BUILD.bazel
@@ -420,7 +420,7 @@ pkg_files(
         "src/test/java/**/*.java",
         "src/test/proto/**/*.proto",
     ]) + [
-        "BUILD",
+        "BUILD.bazel",
         "generate-sources-build.xml",
         "generate-test-sources-build.xml",
         "pom.xml",
diff --git a/java/internal/BUILD b/java/internal/BUILD.bazel
similarity index 92%
rename from java/internal/BUILD
rename to java/internal/BUILD.bazel
index d2e0b538f..662dabd56 100644
--- a/java/internal/BUILD
+++ b/java/internal/BUILD.bazel
@@ -5,7 +5,7 @@ load("@rules_pkg//:mappings.bzl", "pkg_files", "strip_prefix")
 pkg_files(
     name = "dist_files",
     srcs = [
-        "BUILD",
+        "BUILD.bazel",
         "testing.bzl",
     ],
     strip_prefix = strip_prefix.from_root(""),
diff --git a/java/kotlin-lite/BUILD b/java/kotlin-lite/BUILD.bazel
similarity index 99%
rename from java/kotlin-lite/BUILD
rename to java/kotlin-lite/BUILD.bazel
index 18914441c..88f6014fc 100644
--- a/java/kotlin-lite/BUILD
+++ b/java/kotlin-lite/BUILD.bazel
@@ -191,7 +191,7 @@ pkg_files(
         "src/main/kotlin/com/google/protobuf/*.kt",
         "src/test/kotlin/**/*.kt",
     ]) + [
-        "BUILD",
+        "BUILD.bazel",
         "generate-sources-build.xml",
         "generate-test-sources-build.xml",
         "lite.awk",
diff --git a/java/kotlin/BUILD b/java/kotlin/BUILD.bazel
similarity index 99%
rename from java/kotlin/BUILD
rename to java/kotlin/BUILD.bazel
index c8aae0a04..c48cb0376 100644
--- a/java/kotlin/BUILD
+++ b/java/kotlin/BUILD.bazel
@@ -303,7 +303,7 @@ pkg_files(
         "src/test/kotlin/**/*.kt",
         "src/test/proto/**/*.proto",
     ]) + [
-        "BUILD",
+        "BUILD.bazel",
         "generate-sources-build.xml",
         "generate-test-sources-build.xml",
         "pom.xml",
diff --git a/java/lite/BUILD b/java/lite/BUILD.bazel
similarity index 99%
rename from java/lite/BUILD
rename to java/lite/BUILD.bazel
index 6ff858e3f..b492cdda7 100644
--- a/java/lite/BUILD
+++ b/java/lite/BUILD.bazel
@@ -83,7 +83,7 @@ pkg_files(
     srcs = glob([
         "**/*.java",
     ]) + [
-        "BUILD",
+        "BUILD.bazel",
         "generate-sources-build.xml",
         "generate-test-sources-build.xml",
         "lite.awk",
diff --git a/java/util/BUILD b/java/util/BUILD.bazel
similarity index 99%
rename from java/util/BUILD
rename to java/util/BUILD.bazel
index 820adb9a0..ac9b5fde3 100644
--- a/java/util/BUILD
+++ b/java/util/BUILD.bazel
@@ -83,7 +83,7 @@ pkg_files(
         "src/test/**/*.java",
         "src/test/**/*.proto",
     ]) + [
-        "BUILD",
+        "BUILD.bazel",
         "pom.xml",
         "pom_template.xml",
     ],
diff --git a/objectivec/BUILD b/objectivec/BUILD.bazel
similarity index 99%
rename from objectivec/BUILD
rename to objectivec/BUILD.bazel
index 7b0ede686..c18788f40 100644
--- a/objectivec/BUILD
+++ b/objectivec/BUILD.bazel
@@ -111,7 +111,7 @@ pkg_files(
         "Tests/*.proto",
     ]) + [
         ".clang-format",
-        "BUILD",
+        "BUILD.bazel",
         "README.md",
         "Tests/golden_message",
         "Tests/golden_packed_fields_message",
diff --git a/php/BUILD b/php/BUILD.bazel
similarity index 97%
rename from php/BUILD
rename to php/BUILD.bazel
index cf94be1cd..346095957 100644
--- a/php/BUILD
+++ b/php/BUILD.bazel
@@ -14,7 +14,7 @@ pkg_files(
         "tests/*.sh",
         "tests/proto/**/*.proto",
     ]) + [
-        "BUILD",
+        "BUILD.bazel",
         "README.md",
         "REFCOUNTING.md",
         "composer.json",
diff --git a/pkg/BUILD b/pkg/BUILD.bazel
similarity index 100%
rename from pkg/BUILD
rename to pkg/BUILD.bazel
diff --git a/ruby/BUILD b/ruby/BUILD.bazel
similarity index 97%
rename from ruby/BUILD
rename to ruby/BUILD.bazel
index 1884c3983..fe336e549 100644
--- a/ruby/BUILD
+++ b/ruby/BUILD.bazel
@@ -14,7 +14,7 @@ pkg_files(
         "tests/*.rb",
     ]) + [
         ".gitignore",
-        "BUILD",
+        "BUILD.bazel",
         "Gemfile",
         "README.md",
         "Rakefile",
diff --git a/third_party/BUILD b/third_party/BUILD.bazel
similarity index 100%
rename from third_party/BUILD
rename to third_party/BUILD.bazel
diff --git a/third_party/utf8_range/BUILD b/third_party/utf8_range/BUILD.bazel
similarity index 100%
rename from third_party/utf8_range/BUILD
rename to third_party/utf8_range/BUILD.bazel
diff --git a/toolchain/BUILD b/toolchain/BUILD.bazel
similarity index 100%
rename from toolchain/BUILD
rename to toolchain/BUILD.bazel
diff --git a/util/python/BUILD b/util/python/BUILD.bazel
similarity index 96%
rename from util/python/BUILD
rename to util/python/BUILD.bazel
index 85ede91c5..071efd20b 100644
--- a/util/python/BUILD
+++ b/util/python/BUILD.bazel
@@ -1,6 +1,6 @@
 load("@rules_cc//cc:defs.bzl", "cc_library")
 
-exports_files(["BUILD"])
+exports_files(["BUILD.bazel"])
 
 # This is a placeholder for python headers. Projects needing to use
 # fast cpp protos in protobuf's python interface should build with