diff --git a/Dependencies.txt b/Dependencies.txt
index 7e6880fa81..fb93cab93d 100644
--- a/Dependencies.txt
+++ b/Dependencies.txt
@@ -1,6 +1,6 @@
 ZLIB=1.3.1
 abseil-cpp=20250814.1
-Protobuf=v32.0
+Protobuf=v33.1
 Eigen=3.4.0
 Re2=2025-08-12
 CoinUtils=2.11.12
diff --git a/cmake/dependencies/CMakeLists.txt b/cmake/dependencies/CMakeLists.txt
index 67df638983..78404ec197 100644
--- a/cmake/dependencies/CMakeLists.txt
+++ b/cmake/dependencies/CMakeLists.txt
@@ -141,12 +141,12 @@ if(BUILD_Protobuf)
   FetchContent_Declare(
     Protobuf
     GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-    GIT_TAG "v32.0"
+    GIT_TAG "v33.1"
     GIT_SHALLOW TRUE
     GIT_SUBMODULES ""
     UPDATE_COMMAND git reset --hard
     PATCH_COMMAND git apply --ignore-whitespace
-    "${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v32.0.patch"
+    "${CMAKE_CURRENT_LIST_DIR}/../../patches/protobuf-v33.1.patch"
     OVERRIDE_FIND_PACKAGE # Make package visible for "protobuf-matchers" below
   )
   set(protobuf_BUILD_TESTS OFF)
diff --git a/cmake/host.CMakeLists.txt b/cmake/host.CMakeLists.txt
index e524c1edec..b5d9951600 100644
--- a/cmake/host.CMakeLists.txt
+++ b/cmake/host.CMakeLists.txt
@@ -121,11 +121,11 @@ list(APPEND CMAKE_MESSAGE_INDENT "  ")
 FetchContent_Declare(
   protobuf
   GIT_REPOSITORY "https://github.com/protocolbuffers/protobuf.git"
-  GIT_TAG "v32.0"
+  GIT_TAG "v33.1"
   GIT_SHALLOW TRUE
   GIT_SUBMODULES ""
   PATCH_COMMAND git apply --ignore-whitespace
-  "${CMAKE_CURRENT_LIST_DIR}/@PATCHES_PATH@/protobuf-v32.0.patch"
+  "${CMAKE_CURRENT_LIST_DIR}/@PATCHES_PATH@/protobuf-v33.1.patch"
 )
 set(protobuf_BUILD_TESTS OFF)
 set(protobuf_BUILD_SHARED_LIBS ON)
diff --git a/ortools/dotnet/Google.OrTools-full.csproj.in b/ortools/dotnet/Google.OrTools-full.csproj.in
index 5ac80e65e3..69f30826cc 100644
--- a/ortools/dotnet/Google.OrTools-full.csproj.in
+++ b/ortools/dotnet/Google.OrTools-full.csproj.in
@@ -184,7 +184,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.32.0"/>
+    <PackageReference Include="Google.Protobuf" Version="3.33.1"/>
   </ItemGroup>
 
   <!-- Need to add required runtime dependencies so Meta-Project will pull runtime Nuget(s) -->
diff --git a/ortools/dotnet/Google.OrTools-local.csproj.in b/ortools/dotnet/Google.OrTools-local.csproj.in
index edff73523c..6dcb5f1cb4 100644
--- a/ortools/dotnet/Google.OrTools-local.csproj.in
+++ b/ortools/dotnet/Google.OrTools-local.csproj.in
@@ -172,7 +172,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.32.0"/>
+    <PackageReference Include="Google.Protobuf" Version="3.33.1"/>
   </ItemGroup>
 
   <!-- Need to add required runtime dependencies so Meta-Project will pull runtime Nuget(s) -->
diff --git a/ortools/java/pom-full.xml.in b/ortools/java/pom-full.xml.in
index 397c11e455..17b9b72db4 100644
--- a/ortools/java/pom-full.xml.in
+++ b/ortools/java/pom-full.xml.in
@@ -109,7 +109,7 @@
   <dependency>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-java</artifactId>
-    <version>4.32.0</version>
+    <version>4.33.1</version>
   </dependency>
 </dependencies>
 
diff --git a/ortools/java/pom-local.xml.in b/ortools/java/pom-local.xml.in
index 06e1060664..af5a2d415f 100644
--- a/ortools/java/pom-local.xml.in
+++ b/ortools/java/pom-local.xml.in
@@ -81,7 +81,7 @@
   <dependency>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-java</artifactId>
-    <version>4.32.0</version>
+    <version>4.33.1</version>
   </dependency>
 </dependencies>
 
diff --git a/ortools/python/setup.py.in b/ortools/python/setup.py.in
index b778bff4b1..00ca709220 100644
--- a/ortools/python/setup.py.in
+++ b/ortools/python/setup.py.in
@@ -46,7 +46,7 @@ setup(
         'absl-py >= 2.0.0',
         'numpy >= 2.0.2',
         'pandas >= 2.0.0',
-        'protobuf >= 6.32.0,<6.33',
+        'protobuf >= 6.33.1,<6.34',
         'typing-extensions >= 4.12',
         'immutabledict >= 3.0.0',
     ],
diff --git a/patches/fuzztest-2025-08-05.patch b/patches/fuzztest-2025-08-05.patch
index 7551b5fb89..1245eef824 100644
--- a/patches/fuzztest-2025-08-05.patch
+++ b/patches/fuzztest-2025-08-05.patch
@@ -35,7 +35,7 @@ index d8565c0..24b7f52 100644
  
  set(proto_URL https://github.com/protocolbuffers/protobuf.git)
 -set(proto_TAG v30.2)
-+set(proto_TAG v32.0)
++set(proto_TAG v33.1)
  
  set(nlohmann_json_URL https://github.com/nlohmann/json.git)
  set(nlohmann_json_TAG v3.11.3)
diff --git a/patches/protobuf-v32.0.patch b/patches/protobuf-v33.1.patch
similarity index 100%
rename from patches/protobuf-v32.0.patch
rename to patches/protobuf-v33.1.patch