diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ec30ced7..767ebe23 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -171,18 +171,12 @@ jobs:
 
   cloud-test:
     # Secrets are unavailable to workflows from forks.
-    if: ${{ github.event.pull_request.head.repo.full_name == '' || github.event.pull_request.head.repo.full_name == 'temporalio/sdk-ruby' }}
+    if: ${{ (github.event.pull_request.head.repo.full_name == '' || github.event.pull_request.head.repo.full_name == 'temporalio/sdk-ruby') && github.actor != 'dependabot[bot]' }}
     runs-on: ubuntu-latest
-    timeout-minutes: 30
-    concurrency:
-      group: sdk-ruby-cloud-test
-      cancel-in-progress: false
+    timeout-minutes: 45
     env:
       TEMPORAL_TEST_ENV_CONFIG_SERVER: "1"
-      TEMPORAL_ADDRESS: ca-central-1.aws.api.temporal.io:7233
-      TEMPORAL_NAMESPACE: ${{ vars.TEMPORAL_CLIENT_NAMESPACE }}
-      TEMPORAL_API_KEY: ${{ secrets.TEMPORAL_CLIENT_CLOUD_API_KEY }}
-      TEMPORAL_GRPC_META_TEMPORAL_NAMESPACE: ${{ vars.TEMPORAL_CLIENT_NAMESPACE }}
+      TEMPORAL_CLIENT_CLOUD_API_VERSION: v0.19.1
     steps:
       - name: Checkout repository
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
@@ -215,12 +209,49 @@ jobs:
         working-directory: ./temporalio
         run: bundle exec rake compile
 
+      - name: Generate Cloud test certificates
+        run: |
+          cert_dir="$RUNNER_TEMP/cloud-test-certs"
+          mkdir "$cert_dir"
+          openssl req -x509 -newkey rsa:2048 -nodes -days 1 \
+            -keyout "$cert_dir/ca.key" -out "$cert_dir/ca.pem" \
+            -subj '/CN=Temporal Ruby SDK Cloud CI CA'
+          openssl req -newkey rsa:2048 -nodes \
+            -keyout "$cert_dir/client.key" -out "$cert_dir/client.csr" \
+            -subj '/CN=Temporal Ruby SDK Cloud CI'
+          openssl x509 -req -days 1 -in "$cert_dir/client.csr" \
+            -CA "$cert_dir/ca.pem" -CAkey "$cert_dir/ca.key" -CAcreateserial \
+            -out "$cert_dir/client.pem" -extfile <(printf 'extendedKeyUsage=clientAuth')
+          {
+            echo "TEMPORAL_CLOUD_CLIENT_CA_PATH=$cert_dir/ca.pem"
+            echo "TEMPORAL_TLS_CLIENT_CERT_PATH=$cert_dir/client.pem"
+            echo "TEMPORAL_TLS_CLIENT_KEY_PATH=$cert_dir/client.key"
+          } >> "$GITHUB_ENV"
+
+      - name: Create Cloud namespace
+        id: create-cloud-namespace
+        working-directory: ./temporalio
+        run: bundle exec ruby extra/cloud_namespace.rb create
+        env:
+          TEMPORAL_CLIENT_CLOUD_API_KEY: ${{ secrets.TEMPORAL_CLIENT_CLOUD_API_KEY }}
+
       - name: Test Ruby against Temporal Cloud
-        if: ${{ env.TEMPORAL_NAMESPACE != '' && env.TEMPORAL_API_KEY != '' }}
         working-directory: ./temporalio
-        timeout-minutes: 20
+        timeout-minutes: 15
+        env:
+          TEMPORAL_ADDRESS: ${{ steps.create-cloud-namespace.outputs.namespace }}.tmprl.cloud:7233
+          TEMPORAL_NAMESPACE: ${{ steps.create-cloud-namespace.outputs.namespace }}
         run: bundle exec rake test TEST=test/worker_workflow_test.rb TESTOPTS="--name=/WorkerWorkflowTest#test_simple/"
 
-      - name: Report unavailable Cloud configuration
-        if: ${{ env.TEMPORAL_NAMESPACE == '' || env.TEMPORAL_API_KEY == '' }}
-        run: echo "Temporal Cloud test skipped because its namespace or API key is unavailable"
+      - name: Delete Cloud namespace
+        id: delete-cloud-namespace
+        if: ${{ always() && steps.create-cloud-namespace.outputs.namespace != '' }}
+        continue-on-error: true
+        working-directory: ./temporalio
+        run: bundle exec ruby extra/cloud_namespace.rb delete "${{ steps.create-cloud-namespace.outputs.namespace }}"
+        env:
+          TEMPORAL_CLIENT_CLOUD_API_KEY: ${{ secrets.TEMPORAL_CLIENT_CLOUD_API_KEY }}
+
+      - name: Report Cloud namespace cleanup failure
+        if: ${{ always() && steps.delete-cloud-namespace.outcome == 'failure' }}
+        run: echo "::warning title=Cloud namespace cleanup failed::Failed to delete Cloud namespace ${{ steps.create-cloud-namespace.outputs.namespace }}"
diff --git a/temporalio/extra/cloud_namespace.rb b/temporalio/extra/cloud_namespace.rb
new file mode 100644
index 00000000..fd320561
--- /dev/null
+++ b/temporalio/extra/cloud_namespace.rb
@@ -0,0 +1,125 @@
+# frozen_string_literal: true
+
+require 'securerandom'
+require 'temporalio/api'
+require 'temporalio/client'
+require 'timeout'
+
+# Keeps Cloud CI isolated by provisioning and deleting a namespace for each run.
+module CloudNamespace
+  CLOUD_API_TARGET = 'saas-api.tmprl.cloud:443'
+  CLOUD_REGION = 'aws-ca-central-1'
+  OPERATION_TIMEOUT_SECONDS = 10 * 60
+  FAILED_OPERATION_STATES = %i[STATE_FAILED STATE_CANCELLED STATE_REJECTED].freeze
+
+  class << self
+    # Keep command dispatch separate so the lifecycle can run inside the repository's Ruby bundle.
+    def run(args)
+      case args
+      in ['create']
+        create
+      in ['delete', namespace]
+        delete(namespace)
+      else
+        raise ArgumentError, 'Usage: cloud_namespace.rb create|delete <namespace>'
+      end
+    end
+
+    # Emit the namespace before polling so cleanup can run if provisioning later fails.
+    def create
+      service = cloud_service
+      namespace_name = "sdk-ruby-ci-#{required_env('GITHUB_RUN_ID')}-#{required_env('GITHUB_RUN_ATTEMPT')}"
+      result = service.create_namespace(
+        Temporalio::Api::Cloud::CloudService::V1::CreateNamespaceRequest.new(
+          spec: Temporalio::Api::Cloud::Namespace::V1::NamespaceSpec.new(
+            name: namespace_name,
+            replicas: [Temporalio::Api::Cloud::Namespace::V1::ReplicaSpec.new(region: CLOUD_REGION)],
+            retention_days: 1,
+            mtls_auth: Temporalio::Api::Cloud::Namespace::V1::MtlsAuthSpec.new(
+              accepted_client_ca: File.binread(required_env('TEMPORAL_CLOUD_CLIENT_CA_PATH')),
+              enabled: true
+            )
+          ),
+          async_operation_id: SecureRandom.uuid
+        )
+      )
+      namespace = result.namespace
+      raise 'Create namespace response did not include a namespace' if namespace.nil? || namespace.empty?
+
+      File.open(required_env('GITHUB_OUTPUT'), 'a') { |output| output.puts("namespace=#{namespace}") }
+      wait_for_operation(service, result.async_operation)
+    end
+
+    # Read the current resource version because Cloud uses optimistic concurrency for deletion.
+    def delete(namespace)
+      service = cloud_service
+      existing = service.get_namespace(
+        Temporalio::Api::Cloud::CloudService::V1::GetNamespaceRequest.new(namespace:)
+      ).namespace
+      resource_version = existing&.resource_version
+      if resource_version.nil? || resource_version.empty?
+        raise "Cloud namespace #{namespace} did not include a resource version"
+      end
+
+      result = service.delete_namespace(
+        Temporalio::Api::Cloud::CloudService::V1::DeleteNamespaceRequest.new(
+          namespace:,
+          resource_version:,
+          async_operation_id: SecureRandom.uuid
+        )
+      )
+      wait_for_operation(service, result.async_operation)
+    end
+
+    # Honor server polling guidance while bounding the overall asynchronous operation.
+    def wait_for_operation(service, operation)
+      operation_id = operation&.id
+      raise 'Cloud operation response did not include an ID' if operation_id.nil? || operation_id.empty?
+
+      deadline = Process.clock_gettime(Process::CLOCK_MONOTONIC) + OPERATION_TIMEOUT_SECONDS
+      loop do
+        operation = service.get_async_operation(
+          Temporalio::Api::Cloud::CloudService::V1::GetAsyncOperationRequest.new(
+            async_operation_id: operation_id
+          )
+        ).async_operation
+        raise "Cloud operation #{operation_id} could not be read" unless operation
+        return if operation.state == :STATE_FULFILLED
+
+        if FAILED_OPERATION_STATES.include?(operation.state)
+          state = operation.state.to_s.delete_prefix('STATE_').downcase
+          raise "Cloud operation #{operation_id} #{state}: #{operation.failure_reason}"
+        end
+
+        remaining = deadline - Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        raise Timeout::Error, "Timed out waiting for Cloud operation #{operation_id}" if remaining <= 0
+
+        duration = operation.check_duration
+        delay = duration ? duration.seconds + (duration.nanos / 1_000_000_000.0) : 10
+        minimum_delay = [1, remaining].min
+        Kernel.sleep(delay.clamp(minimum_delay, remaining))
+      end
+    end
+
+    private
+
+    def cloud_service
+      Temporalio::Client::Connection.new(
+        target_host: CLOUD_API_TARGET,
+        api_key: required_env('TEMPORAL_CLIENT_CLOUD_API_KEY'),
+        rpc_metadata: {
+          'temporal-cloud-api-version' => required_env('TEMPORAL_CLIENT_CLOUD_API_VERSION')
+        }
+      ).cloud_service
+    end
+
+    def required_env(name)
+      value = ENV.fetch(name, '')
+      return value unless value.empty?
+
+      raise "Missing required environment variable #{name}"
+    end
+  end
+end
+
+CloudNamespace.run(ARGV) if $PROGRAM_NAME == __FILE__