diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6ac2e90b91d..ce892c54377 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -191,11 +191,6 @@ jobs:
       - name: Install requirements
         run: |
           pip install -r dev_tools/requirements/deps/protos.txt
-          sudo apt install curl gnupg
-          curl -fsSL https://bazel.build/bazel-release.pub.gpg | gpg --dearmor > bazel.gpg
-          sudo mv bazel.gpg /etc/apt/trusted.gpg.d/
-          echo "deb [arch=amd64] https://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel.list
-          sudo apt update && sudo apt install bazel
       - name: Build protos
         run: check/build-changed-protos
   coverage:
@@ -335,4 +330,4 @@ jobs:
       - name: Install npm dependencies
         run: check/npm ci
       - name: Test
-        run: check/ts-coverage
\ No newline at end of file
+        run: check/ts-coverage
diff --git a/WORKSPACE b/WORKSPACE
deleted file mode 100644
index dbc8e4fbc88..00000000000
--- a/WORKSPACE
+++ /dev/null
@@ -1,62 +0,0 @@
-# General bazel utility
-load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")
-
-# =========================
-# Proto dependencies below.
-# =========================
-
-# Native proto_library is deprecated; this is a replacement.  See
-# https://docs.bazel.build/versions/master/be/protocol-buffer.html#proto_library
-http_archive(
-    name = "rules_proto",
-    sha256 = "602e7161d9195e50246177e7c55b2f39950a9cf7366f74ed5f22fd45750cd208",
-    strip_prefix = "rules_proto-97d8af4dc474595af3900dd85cb3a29ad28cc313",
-    urls = [
-        "https://mirror.bazel.build/github.com/bazelbuild/rules_proto/archive/97d8af4dc474595af3900dd85cb3a29ad28cc313.tar.gz",
-        "https://github.com/bazelbuild/rules_proto/archive/97d8af4dc474595af3900dd85cb3a29ad28cc313.tar.gz",
-    ],
-)
-
-# Use this zlib rule that depends on github since it is more reliable than zlib.net.
-http_archive(
-    name = "zlib",
-    build_file = "@com_google_protobuf//:third_party/zlib.BUILD",
-    sha256 = "629380c90a77b964d896ed37163f5c3a34f6e6d897311f1df2a7016355c45eff",
-    strip_prefix = "zlib-1.2.11",
-    urls = ["https://github.com/madler/zlib/archive/v1.2.11.tar.gz"],
-)
-
-load("@rules_proto//proto:repositories.bzl", "rules_proto_dependencies", "rules_proto_toolchains")
-rules_proto_dependencies()
-rules_proto_toolchains()
-
-# In protobuf 3.8.0, this function is used only to load the zlib dependency.
-load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")
-protobuf_deps()
-
-http_archive(
-    name = "bazel_skylib",
-    url = "https://github.com/bazelbuild/bazel-skylib/releases/download/0.9.0/bazel_skylib-0.9.0.tar.gz",
-    sha256 = "1dde365491125a3db70731e25658dfdd3bc5dbdfd11b840b3e987ecf043c7ca0",
-)
-
-# Python compatibility.
-http_archive(
-    name = "six_archive",
-    build_file = "@com_google_protobuf//:six.BUILD",
-    sha256 = "105f8d68616f8248e24bf0e9372ef04d3cc10104f1980f54d57b2ce73a5ad56a",
-    url = "https://pypi.python.org/packages/source/s/six/six-1.10.0.tar.gz#md5=34eed507548117b2ab523ab14b2f8b55",
-)
-bind(
-    name = "six",
-    actual = "@six_archive//:six",
-)
-
-# proto_library, py_proto_library, and cc_proto_library rules implicitly
-# depend on @com_google_protobuf for protoc and proto runtimes.
-http_archive(
-    name = "com_google_protobuf",
-    sha256 = "1e622ce4b84b88b6d2cdf1db38d1a634fe2392d74f0b7b74ff98f3a51838ee53",
-    strip_prefix = "protobuf-3.8.0",
-    urls = ["https://github.com/google/protobuf/archive/v3.8.0.zip"],
-)
diff --git a/check/build-changed-protos b/check/build-changed-protos
index 7b2b3657e4a..b48824abafa 100755
--- a/check/build-changed-protos
+++ b/check/build-changed-protos
@@ -71,30 +71,9 @@ if [[ ! -z "$changed" ]]; then
     done
 fi
 
-# Check if any of the build files have changed.
-build_changed=$(git diff --name-only ${rev} -- \
-    | grep "google/api/.*BUILD$" \
-    | sed -e "s/BUILD//")
-
-if [[ -z "$build_changed" ]]; then
-    echo -e "No BUILD files changed."
-else
-    # Build all the targets for the changed BUILD rule.
-    echo -e "BUILD file changed in directories: '${build_changed[@]}'"
-    for build_prefix in $build_changed
-    do
-        (set -x; bazel build "${build_prefix}...:*")
-    done
-fi
-
-# We potentially will attempt to build a second time, but this is not
-# a problem as bazel returns immediately.
+# We potentially will attempt to build a second time.
 for base in $changed
 do
-    (set -x; bazel build "${base}_proto"; \
-    bazel build "${base}_py_proto"; \
-    bazel build "${base}_cc_proto")
-
     python -m grpc_tools.protoc -I=cirq-google --python_out=cirq-google --mypy_out=cirq-google ${base}.proto
 done
 
@@ -109,4 +88,4 @@ if [[ ! -z "$untracked" ]]; then
         echo -e "\033[31m   ${generated}\033[0m"
     done
     exit 1
-fi
\ No newline at end of file
+fi
diff --git a/check/build-protos b/check/build-protos
deleted file mode 100755
index 65ccc8a3467..00000000000
--- a/check/build-protos
+++ /dev/null
@@ -1,30 +0,0 @@
-#!/usr/bin/env bash
-
-################################################################################
-# Runs bazel build for proto files in cirq/google/api/*
-#
-# See build-changed-protos for a version of this that only builds changed
-# protos.
-#
-# Usage:
-#     check/build-protos
-################################################################################
-
-# Get the working directory to the repo root.
-cd "$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
-cd "$(git rev-parse --show-toplevel)"
-
-protos=$(find -type f -name "*.proto" -printf '%P\n' \
-    | grep "google/api/.*\.proto$" \
-    | sed -e "s/\.proto$//")
-for base in $protos:
-do
-    echo -e "Found proto: '${base}.proto'"
-done
-
-for base in $protos
-do
-    bazel build "${base}_proto"
-    bazel build "${base}_py_proto"
-    bazel build "${base}_cc_proto"
-done
diff --git a/cirq-google/cirq_google/api/v1/BUILD b/cirq-google/cirq_google/api/v1/BUILD
deleted file mode 100644
index 5a1b72d9328..00000000000
--- a/cirq-google/cirq_google/api/v1/BUILD
+++ /dev/null
@@ -1,62 +0,0 @@
-package(default_visibility = ["//visibility:public"])
-
-load("@com_google_protobuf//:protobuf.bzl", "py_proto_library")
-
-proto_library(
-    name = "operations_proto",
-    srcs = ["operations.proto"],
-)
-
-py_proto_library(
-    name = "operations_py_proto",
-    srcs = ["operations.proto"],
-)
-
-cc_proto_library(
-    name = "operations_cc_proto",
-    deps = [
-        ":operations_proto",
-    ],
-)
-
-proto_library(
-    name = "params_proto",
-    srcs = ["params.proto"],
-)
-
-py_proto_library(
-    name = "params_py_proto",
-    srcs = ["params.proto"],
-)
-
-cc_proto_library(
-    name = "params_cc_proto",
-    deps = [
-        ":params_proto",
-    ],
-)
-
-proto_library(
-    name = "program_proto",
-    srcs = ["program.proto"],
-    deps = [
-        ":operations_proto",
-        ":params_proto",
-    ],
-)
-
-py_proto_library(
-    name = "program_py_proto",
-    srcs = ["program.proto"],
-    deps = [
-        ":operations_py_proto",
-        ":params_py_proto",
-    ],
-)
-
-cc_proto_library(
-    name = "program_cc_proto",
-    deps = [
-        ":program_proto",
-    ],
-)
diff --git a/cirq-google/cirq_google/api/v2/BUILD b/cirq-google/cirq_google/api/v2/BUILD
deleted file mode 100644
index a99f5d2ca39..00000000000
--- a/cirq-google/cirq_google/api/v2/BUILD
+++ /dev/null
@@ -1,153 +0,0 @@
-package(default_visibility = ["//visibility:public"])
-
-load("@com_google_protobuf//:protobuf.bzl", "py_proto_library")
-
-proto_library(
-    name = "batch_proto",
-    srcs = ["batch.proto"],
-    deps = [
-        ":program_proto",
-        ":result_proto",
-        ":run_context_proto"
-    ],
-)
-
-py_proto_library(
-    name = "batch_py_proto",
-    srcs = ["batch.proto"],
-    deps = [
-        ":program_py_proto",
-        ":result_py_proto",
-        ":run_context_py_proto"
-    ],
-)
-
-cc_proto_library(
-    name = "batch_cc_proto",
-    deps = [
-        ":batch_proto"
-    ],
-)
-
-
-proto_library(
-    name = "calibration_proto",
-    srcs = ["calibration.proto"],
-    deps = [
-        ":metrics_proto",
-        ":program_proto"
-    ],
-)
-
-py_proto_library(
-    name = "calibration_py_proto",
-    srcs = ["calibration.proto"],
-    deps = [
-        ":metrics_py_proto",
-        ":program_py_proto"
-    ],
-)
-
-cc_proto_library(
-    name = "calibration_cc_proto",
-    deps = [
-        ":calibration_proto"
-    ],
-)
-
-proto_library(
-    name = "device_proto",
-    srcs = ["device.proto"],
-)
-
-py_proto_library(
-    name = "device_py_proto",
-    srcs = ["device.proto"],
-)
-
-cc_proto_library(
-    name = "device_cc_proto",
-    deps = [
-        ":device_proto"
-    ],
-)
-
-proto_library(
-    name = "metrics_proto",
-    srcs = ["metrics.proto"],
-)
-
-py_proto_library(
-    name = "metrics_py_proto",
-    srcs = ["metrics.proto"],
-)
-
-cc_proto_library(
-    name = "metrics_cc_proto",
-    deps = [
-        ":metrics_proto"
-    ],
-)
-
-proto_library(
-    name = "program_proto",
-    srcs = ["program.proto"],
-)
-
-py_proto_library(
-    name = "program_py_proto",
-    srcs = ["program.proto"],
-)
-
-cc_proto_library(
-    name = "program_cc_proto",
-    deps = [
-        ":program_proto"
-    ],
-)
-
-proto_library(
-    name = "result_proto",
-    srcs = ["result.proto"],
-    deps = [
-        ":program_proto",
-    ],
-)
-
-py_proto_library(
-    name = "result_py_proto",
-    srcs = ["result.proto"],
-    deps = [
-        ":program_py_proto",
-    ],
-)
-
-cc_proto_library(
-    name = "result_cc_proto",
-    deps = [
-        ":result_proto",
-    ],
-)
-
-proto_library(
-    name = "run_context_proto",
-    srcs = ["run_context.proto"],
-    deps = [
-        ":program_proto",
-    ],
-)
-
-py_proto_library(
-    name = "run_context_py_proto",
-    srcs = ["run_context.proto"],
-    deps = [
-        ":program_py_proto",
-    ],
-)
-
-cc_proto_library(
-    name = "run_context_cc_proto",
-    deps = [
-        ":run_context_proto",
-    ],
-)
diff --git a/docs/dev/development.md b/docs/dev/development.md
index 43e314146c9..11cc7e14d3c 100644
--- a/docs/dev/development.md
+++ b/docs/dev/development.md
@@ -151,10 +151,6 @@ Cirq's protobufs live at [cirq/api/google](https://github.com/quantumlib/Cirq/tr
 If any protos are updated, their dependents can be rebuilt by calling the script [dev_tools/build-protos.sh](https://github.com/quantumlib/Cirq/tree/master/dev_tools).
 This script uses grpcio-tools and protobuf version 3.8.0 to generate the python proto api.
 
-Additionally, for workflows that use bazel (relevant for C/C++ code depending on Cirq), we have made available bazel rulesets for generating both python and C/C++ proto apis.
-These rules live in the BUILD files [here](https://github.com/quantumlib/Cirq/tree/master/cirq/api/google/v1) and [here](https://github.com/quantumlib/Cirq/tree/master/cirq/api/google/v2).
-Downstream projects should load Cirq as an [external dependency](https://docs.bazel.build/versions/master/external.html), allowing rules from those BUILD files to be used directly.
-
 ## Continuous integration and local testing
 
 There are a few options for running continuous integration checks, varying from easy and fast to slow and reliable.