diff --git a/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy b/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
index 76f380c94bb8..3a928f2a3229 100644
--- a/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
+++ b/buildSrc/src/main/groovy/org/apache/beam/gradle/BeamModulePlugin.groovy
@@ -3121,10 +3121,11 @@ class BeamModulePlugin implements Plugin<Project> {
             // TODO: https://github.com/apache/beam/issues/29022
             // pip 23.3 is failing due to Hash mismatch between expected SHA of the packaged and actual SHA.
             // until it is resolved on pip's side, don't use pip's cache.
-            // pip 25.1 casues :sdks:python:installGcpTest stuck. Pin to 25.0.1 for now.
+            // Use pip 26.0.1 for improved resolution performance and bug fixes. See #34798.
             args '-c', ". ${project.ext.envdir}/bin/activate && " +
-                "pip install --pre --retries 10 --upgrade pip==25.0.1 --no-cache-dir && " +
-                "pip install --pre --retries 10 --upgrade tox --no-cache-dir"
+                "pip install --pre --retries 10 --upgrade pip==26.0.1 --no-cache-dir && " +
+                "pip install --pre --retries 10 --upgrade tox --no-cache-dir && " +
+                "pip install uv"
           }
         }
         // Gradle will delete outputs whenever it thinks they are stale. Putting a
@@ -3169,9 +3170,19 @@ class BeamModulePlugin implements Plugin<Project> {
             packages += ",${extra}"
           }
 
+          def pythonSdkDir = project.project(":sdks:python").projectDir
+          def constraintsPath = "${pythonSdkDir}/constraints.txt"
+          def constraintFile = project.file(constraintsPath)
+          def constraintFlag = constraintFile.exists() ? "--constraint ${constraintsPath}" : ""
+
+          // Use uv instead of pip - pip was hitting resolution-too-deep on tensorflow->keras->namex/optree.
+          // Include namex/optree as explicit deps to constrain resolution.
+          // --prerelease allow: envoy-data-plane depends on betterproto==2.0.0b6 (beta).
+          def anchorPkgs = "namex==0.0.9 optree==0.16.0"
+          def installCmd = ". ${project.ext.envdir}/bin/activate && uv pip install --prerelease allow ${constraintFlag} ${anchorPkgs} ${distTarBall}[${packages}]".replaceAll(/  +/, ' ').trim()
           project.exec {
             executable 'sh'
-            args '-c', ". ${project.ext.envdir}/bin/activate && pip install --pre --retries 10 ${distTarBall}[${packages}]"
+            args '-c', installCmd
           }
         }
       }
diff --git a/sdks/python/constraints.txt b/sdks/python/constraints.txt
new file mode 100644
index 000000000000..c591d73e48d6
--- /dev/null
+++ b/sdks/python/constraints.txt
@@ -0,0 +1,24 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+# Pins for installGcpTest. numpy handled via setup.py python_version markers.
+# Use google-api-core 2.29.0 for py313 compat (2.16.2 lacks it).
+googleapis-common-protos==1.72.0
+grpc-google-iam-v1>=0.12.4,<1.0.0
+google-api-core==2.29.0
+optree==0.16.0
+namex==0.0.9
diff --git a/sdks/python/container/ml/py310/base_image_requirements.txt b/sdks/python/container/ml/py310/base_image_requirements.txt
index 9817ce616a6c..a89189c903d0 100644
--- a/sdks/python/container/ml/py310/base_image_requirements.txt
+++ b/sdks/python/container/ml/py310/base_image_requirements.txt
@@ -145,7 +145,7 @@ multidict==6.7.1
 namex==0.1.0
 networkx==3.4.2
 nltk==3.9.2
-numpy==2.2.6
+numpy==1.26.4
 oauth2client==4.1.3
 objsize==0.7.1
 opentelemetry-api==1.39.1
diff --git a/sdks/python/container/ml/py310/gpu_image_requirements.txt b/sdks/python/container/ml/py310/gpu_image_requirements.txt
index f43dd2745aba..f02261d99584 100644
--- a/sdks/python/container/ml/py310/gpu_image_requirements.txt
+++ b/sdks/python/container/ml/py310/gpu_image_requirements.txt
@@ -172,7 +172,7 @@ networkx==3.4.2
 ninja==1.13.0
 nltk==3.9.2
 numba==0.61.2
-numpy==2.2.6
+numpy==1.26.4
 nvidia-cublas-cu12==12.6.4.1
 nvidia-cuda-cupti-cu12==12.6.80
 nvidia-cuda-nvrtc-cu12==12.6.77
diff --git a/sdks/python/container/ml/py311/base_image_requirements.txt b/sdks/python/container/ml/py311/base_image_requirements.txt
index 571cdb28c767..78297cd5925c 100644
--- a/sdks/python/container/ml/py311/base_image_requirements.txt
+++ b/sdks/python/container/ml/py311/base_image_requirements.txt
@@ -143,7 +143,7 @@ multidict==6.7.1
 namex==0.1.0
 networkx==3.6.1
 nltk==3.9.2
-numpy==2.4.2
+numpy==1.26.4
 oauth2client==4.1.3
 objsize==0.7.1
 opentelemetry-api==1.39.1
diff --git a/sdks/python/container/ml/py311/gpu_image_requirements.txt b/sdks/python/container/ml/py311/gpu_image_requirements.txt
index f44a8ff9be00..bb9469364878 100644
--- a/sdks/python/container/ml/py311/gpu_image_requirements.txt
+++ b/sdks/python/container/ml/py311/gpu_image_requirements.txt
@@ -170,7 +170,7 @@ networkx==3.6.1
 ninja==1.13.0
 nltk==3.9.2
 numba==0.61.2
-numpy==2.2.6
+numpy==1.26.4
 nvidia-cublas-cu12==12.6.4.1
 nvidia-cuda-cupti-cu12==12.6.80
 nvidia-cuda-nvrtc-cu12==12.6.77
diff --git a/sdks/python/container/ml/py312/base_image_requirements.txt b/sdks/python/container/ml/py312/base_image_requirements.txt
index fdc80fd0ccb4..6f505c817a3b 100644
--- a/sdks/python/container/ml/py312/base_image_requirements.txt
+++ b/sdks/python/container/ml/py312/base_image_requirements.txt
@@ -142,7 +142,7 @@ multidict==6.7.1
 namex==0.1.0
 networkx==3.6.1
 nltk==3.9.2
-numpy==2.4.2
+numpy==1.26.4
 oauth2client==4.1.3
 objsize==0.7.1
 opentelemetry-api==1.39.1
diff --git a/sdks/python/container/ml/py312/gpu_image_requirements.txt b/sdks/python/container/ml/py312/gpu_image_requirements.txt
index a9b13f834d1a..5c711e7fcf18 100644
--- a/sdks/python/container/ml/py312/gpu_image_requirements.txt
+++ b/sdks/python/container/ml/py312/gpu_image_requirements.txt
@@ -169,7 +169,7 @@ networkx==3.6.1
 ninja==1.13.0
 nltk==3.9.2
 numba==0.61.2
-numpy==2.2.6
+numpy==1.26.4
 nvidia-cublas-cu12==12.6.4.1
 nvidia-cuda-cupti-cu12==12.6.80
 nvidia-cuda-nvrtc-cu12==12.6.77
diff --git a/sdks/python/container/py310/base_image_requirements.txt b/sdks/python/container/py310/base_image_requirements.txt
index 1f78a4935f73..8f290074d385 100644
--- a/sdks/python/container/py310/base_image_requirements.txt
+++ b/sdks/python/container/py310/base_image_requirements.txt
@@ -126,7 +126,7 @@ mock==5.2.0
 more-itertools==10.8.0
 multidict==6.7.1
 nltk==3.9.2
-numpy==2.2.6
+numpy==1.26.4
 oauth2client==4.1.3
 objsize==0.7.1
 opentelemetry-api==1.39.1
diff --git a/sdks/python/container/py311/base_image_requirements.txt b/sdks/python/container/py311/base_image_requirements.txt
index e41f72af87e3..ec796606536e 100644
--- a/sdks/python/container/py311/base_image_requirements.txt
+++ b/sdks/python/container/py311/base_image_requirements.txt
@@ -124,7 +124,7 @@ mock==5.2.0
 more-itertools==10.8.0
 multidict==6.7.1
 nltk==3.9.2
-numpy==2.4.2
+numpy==1.26.4
 oauth2client==4.1.3
 objsize==0.7.1
 opentelemetry-api==1.39.1
diff --git a/sdks/python/container/py312/base_image_requirements.txt b/sdks/python/container/py312/base_image_requirements.txt
index 2f7820d01d68..03958cf374e2 100644
--- a/sdks/python/container/py312/base_image_requirements.txt
+++ b/sdks/python/container/py312/base_image_requirements.txt
@@ -123,7 +123,7 @@ mock==5.2.0
 more-itertools==10.8.0
 multidict==6.7.1
 nltk==3.9.2
-numpy==2.4.2
+numpy==1.26.4
 oauth2client==4.1.3
 objsize==0.7.1
 opentelemetry-api==1.39.1
diff --git a/sdks/python/pyproject.toml b/sdks/python/pyproject.toml
index c705dcb438cf..d17bffb8c14e 100644
--- a/sdks/python/pyproject.toml
+++ b/sdks/python/pyproject.toml
@@ -26,8 +26,9 @@ requires = [
     "mypy-protobuf==3.5.0",
     # Avoid https://github.com/pypa/virtualenv/issues/2006
     "distlib==0.3.9",
-    # Numpy headers
-    "numpy>=1.14.3,<2.5.0", # Update setup.py as well.
+    # Numpy headers. py313 requires 2.1+; py<3.13 use 1.x for pandas ABI compat.
+    "numpy>=1.26.0,<2.0.0; python_version < '3.13'",
+    "numpy>=2.1.0; python_version >= '3.13'",
     # having cython here will create wheels that are platform dependent.
     "cython>=3.0,<4",
     ## deps for generating external transform wrappers:
diff --git a/sdks/python/setup.py b/sdks/python/setup.py
index 19aab312f274..828333444064 100644
--- a/sdks/python/setup.py
+++ b/sdks/python/setup.py
@@ -384,9 +384,10 @@ def get_portability_package_data():
           'grpcio>=1.67.0; python_version >= "3.13"',
           'httplib2>=0.8,<0.32.0',
           'jsonpickle>=3.0.0,<4.0.0',
-          # numpy can have breaking changes in minor versions.
-          # Use a strict upper bound.
-          'numpy>=1.14.3,<2.5.0',  # Update pyproject.toml as well.
+          # numpy: py310-312 use 1.x; py313 needs 2.x (1.x unsupported; avoids  # pylint: disable=line-too-long
+          # pandas ABI mismatch).
+          'numpy>=1.26.0,<2.0.0; python_version < "3.13"',
+          'numpy>=2.1.0; python_version >= "3.13"',
           'objsize>=0.6.1,<0.8.0',
           'packaging>=22.0',
           'pillow',
@@ -541,6 +542,9 @@ def get_portability_package_data():
               # tensorflow-transform requires dill, but doesn't set dill as a
               # hard requirement in setup.py.
               'dill',
+              # namex/optree: pin to avoid resolver issues (lack version bounds)  # pylint: disable=line-too-long
+              'namex==0.0.9',
+              'optree==0.16.0',
               'tensorflow-transform',
               # Comment out xgboost as it is breaking presubmit python ml
               # tests due to tag check introduced since pip 24.2
@@ -549,8 +553,13 @@ def get_portability_package_data():
           ] + ml_base,
           'p312_ml_test': [
               'datatable',
+              'namex==0.0.9',
+              'optree==0.16.0',
+          ] + ml_base,
+          'p313_ml_test': [
+              'namex==0.0.9',
+              'optree==0.16.0',
           ] + ml_base,
-          'p313_ml_test': ml_base,
           'aws': ['boto3>=1.9,<2'],
           'azure': [
               'azure-storage-blob>=12.3.2,<13',