diff --git a/MODULE.bazel b/MODULE.bazel
index 1ab4c2b631771..365aecbd27bc5 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -24,7 +24,7 @@ bazel_dep(name = "platforms", version = "0.0.10")
 bazel_dep(name = "bazel_skylib", version = "1.7.1")
 bazel_dep(name = "rules_cc", version = "0.0.9")
 bazel_dep(name = "abseil-cpp", version = "20240722.0", repo_name = "com_google_absl")
-bazel_dep(name = "protobuf", version = "28.2", repo_name = "com_google_protobuf")
+bazel_dep(name = "protobuf", version = "29.0-rc1", repo_name = "com_google_protobuf")
 bazel_dep(name = "boringssl", version = "0.0.0-20230215-5c22014")
 bazel_dep(name = "grpc", version = "1.66.0", repo_name = "com_github_grpc_grpc")
 bazel_dep(name = "nlohmann_json", version = "3.11.3", repo_name = "com_github_nlohmann_json")
diff --git a/bazel/workspace0.bzl b/bazel/workspace0.bzl
index dc02b9acbb323..b324bedf4fd12 100644
--- a/bazel/workspace0.bzl
+++ b/bazel/workspace0.bzl
@@ -135,10 +135,10 @@ def gl_cpp_workspace0(name = None):
         http_archive,
         name = "com_google_protobuf",
         urls = [
-            "https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz",
+            "https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz",
         ],
-        sha256 = "b2340aa47faf7ef10a0328190319d3f3bee1b24f426d4ce8f4253b6f27ce16db",
-        strip_prefix = "protobuf-28.2",
+        sha256 = "32247eed6fa8c9792d2667b9fb306e8403736097226b478711d7f3bfece6fbda",
+        strip_prefix = "protobuf-29.0-rc1",
     )
 
     # Load BoringSSL. This could be automatically loaded by gRPC. But as of
diff --git a/ci/cloudbuild/dockerfiles/demo-debian-bullseye.Dockerfile b/ci/cloudbuild/dockerfiles/demo-debian-bullseye.Dockerfile
index 7b4ed7a63e53f..4ba11eac67768 100644
--- a/ci/cloudbuild/dockerfiles/demo-debian-bullseye.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/demo-debian-bullseye.Dockerfile
@@ -88,7 +88,7 @@ RUN apt-get update && \
 
 # ```bash
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/ci/cloudbuild/dockerfiles/demo-rockylinux-9.Dockerfile b/ci/cloudbuild/dockerfiles/demo-rockylinux-9.Dockerfile
index 46f5bd40aa749..77b1612b3f254 100644
--- a/ci/cloudbuild/dockerfiles/demo-rockylinux-9.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/demo-rockylinux-9.Dockerfile
@@ -87,7 +87,7 @@ RUN curl -fsSL https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz |
 
 # ```bash
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/ci/cloudbuild/dockerfiles/demo-ubuntu-focal.Dockerfile b/ci/cloudbuild/dockerfiles/demo-ubuntu-focal.Dockerfile
index 7d51b84710885..e0a2aa9324299 100644
--- a/ci/cloudbuild/dockerfiles/demo-ubuntu-focal.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/demo-ubuntu-focal.Dockerfile
@@ -56,7 +56,7 @@ RUN curl -fsSL https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz |
 
 # ```bash
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/ci/cloudbuild/dockerfiles/demo-ubuntu-jammy.Dockerfile b/ci/cloudbuild/dockerfiles/demo-ubuntu-jammy.Dockerfile
index 5bd14cf5f735e..810830d2ac933 100644
--- a/ci/cloudbuild/dockerfiles/demo-ubuntu-jammy.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/demo-ubuntu-jammy.Dockerfile
@@ -56,7 +56,7 @@ RUN curl -fsSL https://github.com/abseil/abseil-cpp/archive/20240722.0.tar.gz |
 
 # ```bash
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/ci/cloudbuild/dockerfiles/fedora-latest-cmake.Dockerfile b/ci/cloudbuild/dockerfiles/fedora-latest-cmake.Dockerfile
index 83523e0882a52..081936e3eaccf 100644
--- a/ci/cloudbuild/dockerfiles/fedora-latest-cmake.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/fedora-latest-cmake.Dockerfile
@@ -129,7 +129,7 @@ RUN curl -fsSL https://github.com/nlohmann/json/archive/v3.11.3.tar.gz | \
     ldconfig && cd /var/tmp && rm -fr build
 
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/ci/cloudbuild/dockerfiles/fedora-latest-cxx14.Dockerfile b/ci/cloudbuild/dockerfiles/fedora-latest-cxx14.Dockerfile
index 072505c256555..b1eb2a6161e81 100644
--- a/ci/cloudbuild/dockerfiles/fedora-latest-cxx14.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/fedora-latest-cxx14.Dockerfile
@@ -135,7 +135,7 @@ RUN curl -fsSL https://github.com/nlohmann/json/archive/v3.11.3.tar.gz | \
     cd /var/tmp && rm -fr build
 
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_CXX_STANDARD=14 \
diff --git a/ci/cloudbuild/dockerfiles/fedora-latest-cxx20.Dockerfile b/ci/cloudbuild/dockerfiles/fedora-latest-cxx20.Dockerfile
index d521996f13280..a411ea0091c3f 100644
--- a/ci/cloudbuild/dockerfiles/fedora-latest-cxx20.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/fedora-latest-cxx20.Dockerfile
@@ -137,7 +137,7 @@ RUN curl -fsSL https://github.com/nlohmann/json/archive/v3.11.3.tar.gz | \
     cd /var/tmp && rm -fr build
 
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_CXX_STANDARD=20 \
diff --git a/ci/cloudbuild/dockerfiles/gcc-oldest.Dockerfile b/ci/cloudbuild/dockerfiles/gcc-oldest.Dockerfile
index dd99f9c074348..490235fc64602 100644
--- a/ci/cloudbuild/dockerfiles/gcc-oldest.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/gcc-oldest.Dockerfile
@@ -55,7 +55,7 @@ RUN curl -fsSL https://github.com/google/benchmark/archive/v1.9.0.tar.gz | \
     ldconfig && cd /var/tmp && rm -fr build
 
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/ci/cloudbuild/dockerfiles/ubuntu-20.04-install.Dockerfile b/ci/cloudbuild/dockerfiles/ubuntu-20.04-install.Dockerfile
index 19da06a88d407..268d765acacb1 100644
--- a/ci/cloudbuild/dockerfiles/ubuntu-20.04-install.Dockerfile
+++ b/ci/cloudbuild/dockerfiles/ubuntu-20.04-install.Dockerfile
@@ -121,7 +121,7 @@ RUN curl -fsSL https://github.com/nlohmann/json/archive/v3.11.3.tar.gz | \
     cd /var/tmp && rm -fr build
 
 WORKDIR /var/tmp/build/protobuf
-RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+RUN curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
diff --git a/doc/packaging.md b/doc/packaging.md
index c9f1e0160d50c..3a489e5533b05 100644
--- a/doc/packaging.md
+++ b/doc/packaging.md
@@ -587,7 +587,7 @@ Google Cloud Platform proto files:
 
 ```bash
 mkdir -p $HOME/Downloads/protobuf && cd $HOME/Downloads/protobuf
-curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
@@ -755,7 +755,7 @@ Google Cloud Platform proto files:
 
 ```bash
 mkdir -p $HOME/Downloads/protobuf && cd $HOME/Downloads/protobuf
-curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
@@ -1085,7 +1085,7 @@ to build from source:
 
 ```bash
 mkdir -p $HOME/Downloads/protobuf && cd $HOME/Downloads/protobuf
-curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \
@@ -1260,7 +1260,7 @@ install Protobuf (and any downstream packages) from source.
 
 ```bash
 mkdir -p $HOME/Downloads/protobuf && cd $HOME/Downloads/protobuf
-curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v28.2.tar.gz | \
+curl -fsSL https://github.com/protocolbuffers/protobuf/archive/v29.0-rc1.tar.gz | \
     tar -xzf - --strip-components=1 && \
     cmake \
         -DCMAKE_BUILD_TYPE=Release \