diff --git a/.github/workflows/linters.yml b/.github/workflows/linters.yml
index 14aed9bfddf..c7569b89abf 100644
--- a/.github/workflows/linters.yml
+++ b/.github/workflows/linters.yml
@@ -77,6 +77,13 @@ jobs:
         run: |
           make lint-py-build || true
           NODE=$(command -v node) make lint-py
+  lint-sh:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - run: shellcheck -V
+      - name: Lint Shell scripts
+        run: tools/lint-sh.js .
 
   lint-codeowners:
     runs-on: ubuntu-latest
diff --git a/tools/actions/commit-queue.sh b/tools/actions/commit-queue.sh
index 9a432237c18..e0dc01dd526 100755
--- a/tools/actions/commit-queue.sh
+++ b/tools/actions/commit-queue.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 set -xe
 
@@ -14,19 +14,19 @@ API_URL=https://api.github.com
 COMMIT_QUEUE_LABEL='commit-queue'
 COMMIT_QUEUE_FAILED_LABEL='commit-queue-failed'
 
-function issueUrl() {
+issueUrl() {
   echo "$API_URL/repos/${OWNER}/${REPOSITORY}/issues/${1}"
 }
 
-function labelsUrl() {
+labelsUrl() {
   echo "$(issueUrl "${1}")/labels"
 }
 
-function commentsUrl() {
+commentsUrl() {
   echo "$(issueUrl "${1}")/comments"
 }
 
-function gitHubCurl() {
+gitHubCurl() {
   url=$1
   method=$2
   shift 2
@@ -67,6 +67,7 @@ for pr in "$@"; do
   if ! tail -n 10 output | grep '. Post "Landed in .*/pull/'"${pr}"; then
     gitHubCurl "$(labelsUrl "$pr")" POST --data '{"labels": ["'"${COMMIT_QUEUE_FAILED_LABEL}"'"]}'
 
+    # shellcheck disable=SC2154
     cqurl="${GITHUB_SERVER_URL}/${OWNER}/${REPOSITORY}/actions/runs/${GITHUB_RUN_ID}"
     jq -n --arg content "<details><summary>Commit Queue failed</summary><pre>$(cat output)</pre><a href='$cqurl'>$cqurl</a></details>" '{body: $content}' > output.json
     cat output.json
diff --git a/tools/actions/start-ci.sh b/tools/actions/start-ci.sh
index 8eb3dae3c5b..72a04b6b321 100755
--- a/tools/actions/start-ci.sh
+++ b/tools/actions/start-ci.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 
 set -xe
 
@@ -10,15 +10,15 @@ REQUEST_CI_LABEL='request-ci'
 REQUEST_CI_FAILED_LABEL='request-ci-failed'
 shift 3
 
-function issueUrl() {
+issueUrl() {
   echo "$API_URL/repos/${OWNER}/${REPOSITORY}/issues/${1}"
 }
 
-function labelsUrl() {
+labelsUrl() {
   echo "$(issueUrl "${1}")/labels"
 }
 
-function commentsUrl() {
+commentsUrl() {
   echo "$(issueUrl "${1}")/comments"
 }
 
@@ -33,7 +33,7 @@ for pr in "$@"; do
   ncu-ci run "$pr" >output 2>&1 || ci_started=no
   cat output
 
-  if [ "$ci_started" == "no" ]; then
+  if [ "$ci_started" = "no" ]; then
     # Do we need to reset?
     curl -sL --request PUT \
        --url "$(labelsUrl "$pr")" \
diff --git a/tools/create_expfile.sh b/tools/create_expfile.sh
index 1daed4b1984..cac20da721b 100755
--- a/tools/create_expfile.sh
+++ b/tools/create_expfile.sh
@@ -37,15 +37,15 @@
 echo "Searching $1 to write out expfile to $2"
 
 # This special sequence must be at the start of the exp file.
-echo "#!." > $2.tmp
+echo "#!." > "$2.tmp"
 
 # Pull the symbols from the .a files.
-find $1 -name "*.a" | grep -v gtest \
+find "$1" -name "*.a" | grep -v gtest \
   | xargs nm -Xany -BCpg \
   | awk '{
       if ((($2 == "T") || ($2 == "D") || ($2 == "B")) &&
           (substr($3,1,1) != ".")) { print $3 }
     }' \
-  | sort -u >> $2.tmp
+  | sort -u >> "$2.tmp"
 
-mv -f $2.tmp $2
+mv -f "$2.tmp" "$2"
diff --git a/tools/lint-pr-commit-message.sh b/tools/lint-pr-commit-message.sh
index 01afd9bab56..443e64469d3 100644
--- a/tools/lint-pr-commit-message.sh
+++ b/tools/lint-pr-commit-message.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 # Shell script to lint the message of the first commit in a pull request.
 #
@@ -13,7 +13,7 @@ PR_ID=$1;
 if [ -z "${PR_ID}" ]; then
   # Attempt to work out the PR number based on current HEAD
   if HEAD_COMMIT="$( git rev-parse HEAD )"; then
-    if SEARCH_RESULTS="$( curl -s ${GH_API_URL}/search/issues?q=sha:${HEAD_COMMIT}+type:pr+repo:nodejs/node )"; then
+    if SEARCH_RESULTS="$( curl -s "${GH_API_URL}/search/issues?q=sha:${HEAD_COMMIT}+type:pr+repo:nodejs/node" )"; then
       if FOUND_PR="$( node -p 'JSON.parse(process.argv[1]).items[0].number' "${SEARCH_RESULTS}" 2> /dev/null )"; then
         PR_ID=${FOUND_PR}
       fi
@@ -26,13 +26,13 @@ if [ -z "${PR_ID}" ]; then
   exit 1
 fi
 
-PATCH=$( curl -sL https://github.com/nodejs/node/pull/${PR_ID}.patch | grep '^From ' )
+PATCH=$( curl -sL "https://github.com/nodejs/node/pull/${PR_ID}.patch" | grep '^From ' )
 if FIRST_COMMIT="$( echo "$PATCH" | awk '/^From [0-9a-f]{40} / { if (count++ == 0) print $2 }' )"; then
-  MESSAGE=$( git show --quiet --format='format:%B' $FIRST_COMMIT )
+  MESSAGE=$( git show --quiet --format='format:%B' "$FIRST_COMMIT" )
   echo "
 *** Linting the first commit message for pull request ${PR_ID}
 *** according to the guidelines at https://goo.gl/p2fr5Q.
-*** Commit message for $(echo $FIRST_COMMIT | cut -c 1-10) is:
+*** Commit message for $(echo "$FIRST_COMMIT" | cut -c 1-10) is:
 ${MESSAGE}
 "
   npx -q core-validate-commit --no-validate-metadata "${FIRST_COMMIT}"
diff --git a/tools/lint-sh.js b/tools/lint-sh.js
new file mode 100755
index 00000000000..7b0beaadfe2
--- /dev/null
+++ b/tools/lint-sh.js
@@ -0,0 +1,185 @@
+#!/usr/bin/env node
+'use strict';
+
+const { execSync, spawn } = require('child_process');
+const { promises: fs, readdirSync, statSync } = require('fs');
+const { extname, join, relative, resolve } = require('path');
+
+const FIX_MODE_ENABLED = process.argv.includes('--fix');
+const USE_NPX = process.argv.includes('--from-npx');
+
+const SHELLCHECK_EXE_NAME = 'shellcheck';
+const SHELLCHECK_OPTIONS = ['--shell=sh', '--severity=info', '--enable=all'];
+if (FIX_MODE_ENABLED) SHELLCHECK_OPTIONS.push('--format=diff');
+else if (process.env.GITHUB_ACTIONS) SHELLCHECK_OPTIONS.push('--format=json');
+
+const SPAWN_OPTIONS = {
+  cwd: null,
+  shell: false,
+  stdio: ['pipe', 'pipe', 'inherit'],
+};
+
+function* findScriptFilesRecursively(dirPath) {
+  const entries = readdirSync(dirPath, { withFileTypes: true });
+
+  for (const entry of entries) {
+    const path = join(dirPath, entry.name);
+
+    if (
+      entry.isDirectory() &&
+      entry.name !== 'build' &&
+      entry.name !== 'changelogs' &&
+      entry.name !== 'deps' &&
+      entry.name !== 'fixtures' &&
+      entry.name !== 'gyp' &&
+      entry.name !== 'inspector_protocol' &&
+      entry.name !== 'node_modules' &&
+      entry.name !== 'out' &&
+      entry.name !== 'tmp'
+    ) {
+      yield* findScriptFilesRecursively(path);
+    } else if (entry.isFile() && extname(entry.name) === '.sh') {
+      yield path;
+    }
+  }
+}
+
+const expectedHashBang = Buffer.from('#!/bin/sh\n');
+async function hasInvalidHashBang(fd) {
+  const { length } = expectedHashBang;
+
+  const actual = Buffer.allocUnsafe(length);
+  await fd.read(actual, 0, length, 0);
+
+  return Buffer.compare(actual, expectedHashBang);
+}
+
+async function checkFiles(...files) {
+  const flags = FIX_MODE_ENABLED ? 'r+' : 'r';
+  await Promise.all(
+    files.map(async (file) => {
+      const fd = await fs.open(file, flags);
+      if (await hasInvalidHashBang(fd)) {
+        if (FIX_MODE_ENABLED) {
+          const file = await fd.readFile();
+
+          const fileContent =
+            file[0] === '#'.charCodeAt() ?
+              file.subarray(file.indexOf('\n') + 1) :
+              file;
+
+          const toWrite = Buffer.concat([expectedHashBang, fileContent]);
+          await fd.truncate(toWrite.length);
+          await fd.write(toWrite, 0, toWrite.length, 0);
+        } else {
+          if (!process.exitCode) process.exitCode = 1;
+          console.error(
+            (process.env.GITHUB_ACTIONS ?
+              `::error file=${file},line=1,col=1::` :
+              'Fixable with --fix: ') +
+              `Invalid hashbang for ${file} (expected /bin/sh).`
+          );
+        }
+      }
+      await fd.close();
+    })
+  );
+
+  const stdout = await new Promise((resolve, reject) => {
+    const SHELLCHECK_EXE =
+      process.env.SHELLCHECK ||
+      execSync('command -v ' + (USE_NPX ? 'npx' : SHELLCHECK_EXE_NAME))
+        .toString()
+        .trim();
+    const NPX_OPTIONS = USE_NPX ? [SHELLCHECK_EXE_NAME] : [];
+
+    const shellcheck = spawn(
+      SHELLCHECK_EXE,
+      [
+        ...NPX_OPTIONS,
+        ...SHELLCHECK_OPTIONS,
+        ...(FIX_MODE_ENABLED ?
+          files.map((filePath) => relative(SPAWN_OPTIONS.cwd, filePath)) :
+          files),
+      ],
+      SPAWN_OPTIONS
+    );
+    shellcheck.once('error', reject);
+
+    let json = '';
+    let childProcess = shellcheck;
+    if (FIX_MODE_ENABLED) {
+      const GIT_EXE =
+        process.env.GIT || execSync('command -v git').toString().trim();
+
+      const gitApply = spawn(GIT_EXE, ['apply'], SPAWN_OPTIONS);
+      shellcheck.stdout.pipe(gitApply.stdin);
+      shellcheck.once('exit', (code) => {
+        if (!process.exitCode && code) process.exitCode = code;
+      });
+      gitApply.stdout.pipe(process.stdout);
+
+      gitApply.once('error', reject);
+      childProcess = gitApply;
+    } else if (process.env.GITHUB_ACTIONS) {
+      shellcheck.stdout.on('data', (chunk) => {
+        json += chunk;
+      });
+    } else {
+      shellcheck.stdout.pipe(process.stdout);
+    }
+    childProcess.once('exit', (code) => {
+      if (!process.exitCode && code) process.exitCode = code;
+      resolve(json);
+    });
+  });
+
+  if (!FIX_MODE_ENABLED && process.env.GITHUB_ACTIONS) {
+    const data = JSON.parse(stdout);
+    for (const { file, line, column, message } of data) {
+      console.error(
+        `::error file=${file},line=${line},col=${column}::` +
+          `${file}:${line}:${column}: ${message}`
+      );
+    }
+  }
+}
+
+const USAGE_STR =
+  `Usage: ${process.argv[1]} <path> [--fix] [--from-npx]\n` +
+  '\n' +
+  'Environment variables:\n' +
+  ' - SHELLCHECK: absolute path to `shellcheck`. If not provided, the\n' +
+  '   script will use the result of `command -v shellcheck`, or\n' +
+  '   `$(command -v npx) shellcheck` if the flag `--from-npx` is provided\n' +
+  '   (may require an internet connection).\n' +
+  ' - GIT: absolute path to `git`. If not provided, the \n' +
+  '   script will use the result of `command -v git`.\n';
+
+if (
+  process.argv.length < 3 ||
+  process.argv.includes('-h') ||
+  process.argv.includes('--help')
+) {
+  console.log(USAGE_STR);
+} else {
+  console.log('Running Shell scripts checker...');
+  const entryPoint = resolve(process.argv[2]);
+  const stats = statSync(entryPoint, { throwIfNoEntry: false });
+
+  function onError(e) {
+    console.log(USAGE_STR);
+    console.error(e);
+    process.exitCode = 1;
+  }
+  if (stats?.isDirectory()) {
+    SPAWN_OPTIONS.cwd = entryPoint;
+    checkFiles(...findScriptFilesRecursively(entryPoint)).catch(onError);
+  } else if (stats?.isFile()) {
+    SPAWN_OPTIONS.cwd = process.cwd();
+    checkFiles(entryPoint).catch(onError);
+  } else {
+    onError(new Error('You must provide a valid directory or file path. ' +
+                      `Received '${process.argv[2]}'.`));
+  }
+}
diff --git a/tools/macos-firewall.sh b/tools/macos-firewall.sh
index 4079dc4d790..5a5ad52c285 100755
--- a/tools/macos-firewall.sh
+++ b/tools/macos-firewall.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 # Script that adds rules to Mac OS X Socket Firewall to avoid
 # popups asking to accept incoming network connections when
 # running tests.
diff --git a/tools/make-v8.sh b/tools/make-v8.sh
index 68222c1cd8b..6b09b515c3d 100755
--- a/tools/make-v8.sh
+++ b/tools/make-v8.sh
@@ -1,16 +1,18 @@
-#!/bin/bash -xe
+#!/bin/sh
+
+set -xe
 
 BUILD_ARCH_TYPE=$1
 V8_BUILD_OPTIONS=$2
 
-cd deps/v8
-find . -type d -name .git | xargs rm -rf
+cd deps/v8 || exit
+find . -type d -name .git -print0 | xargs -0 rm -rf
 tools/node/fetch_deps.py .
 
 ARCH="`arch`"
-if [[ "$ARCH" == "s390x" ]] || [[ "$ARCH" == "ppc64le" ]]; then
+if [ "$ARCH" = "s390x" ] || [ "$ARCH" = "ppc64le" ]; then
   TARGET_ARCH=$ARCH
-  if [[ "$ARCH" == "ppc64le" ]]; then
+  if [ "$ARCH" = "ppc64le" ]; then
     TARGET_ARCH="ppc64"
   fi
   # set paths manually for now to use locally installed gn
@@ -18,20 +20,22 @@ if [[ "$ARCH" == "s390x" ]] || [[ "$ARCH" == "ppc64le" ]]; then
   export LD_LIBRARY_PATH=$BUILD_TOOLS:$LD_LIBRARY_PATH
   # Avoid linking to ccache symbolic links as ccache decides which
   # binary to run based on the name of the link (we always name them gcc/g++).
-  CC_PATH=`which -a $CC gcc | grep -v ccache | head -n 1`
-  CXX_PATH=`which -a $CXX g++ | grep -v ccache | head -n 1`
+  # shellcheck disable=SC2154
+  CC_PATH=`command -v "$CC" gcc | grep -v ccache | head -n 1`
+  # shellcheck disable=SC2154
+  CXX_PATH=`command -v "$CXX" g++ | grep -v ccache | head -n 1`
   rm -f "$BUILD_TOOLS/g++"
   rm -f "$BUILD_TOOLS/gcc"
-  ln -s $CXX_PATH "$BUILD_TOOLS/g++"
-  ln -s $CC_PATH "$BUILD_TOOLS/gcc"
+  ln -s "$CXX_PATH" "$BUILD_TOOLS/g++"
+  ln -s "$CC_PATH" "$BUILD_TOOLS/gcc"
   export PATH=$BUILD_TOOLS:$PATH
 
   g++ --version
   gcc --version
   export PKG_CONFIG_PATH=$BUILD_TOOLS/pkg-config
-  gn gen -v out.gn/$BUILD_ARCH_TYPE --args="is_component_build=false is_debug=false use_goma=false goma_dir=\"None\" use_custom_libcxx=false v8_target_cpu=\"$TARGET_ARCH\" target_cpu=\"$TARGET_ARCH\" v8_enable_backtrace=true"
-  ninja -v -C out.gn/$BUILD_ARCH_TYPE d8 cctest inspector-test
+  gn gen -v "out.gn/$BUILD_ARCH_TYPE" --args="is_component_build=false is_debug=false use_goma=false goma_dir=\"None\" use_custom_libcxx=false v8_target_cpu=\"$TARGET_ARCH\" target_cpu=\"$TARGET_ARCH\" v8_enable_backtrace=true"
+  ninja -v -C "out.gn/$BUILD_ARCH_TYPE" d8 cctest inspector-test
 else
-  PATH=~/_depot_tools:$PATH tools/dev/v8gen.py $BUILD_ARCH_TYPE --no-goma $V8_BUILD_OPTIONS
-  PATH=~/_depot_tools:$PATH ninja -C out.gn/$BUILD_ARCH_TYPE/ d8 cctest inspector-test
+  PATH=~/_depot_tools:$PATH tools/dev/v8gen.py "$BUILD_ARCH_TYPE" --no-goma "$V8_BUILD_OPTIONS"
+  PATH=~/_depot_tools:$PATH ninja -C "out.gn/$BUILD_ARCH_TYPE/" d8 cctest inspector-test
 fi
diff --git a/tools/osx-pkg-postinstall.sh b/tools/osx-pkg-postinstall.sh
index 8212c27f8e8..971da3a88a7 100644
--- a/tools/osx-pkg-postinstall.sh
+++ b/tools/osx-pkg-postinstall.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 # TODO Can this be done inside the .pmdoc?
 # TODO Can we extract $PREFIX from the installer?
-cd /usr/local/bin
+cd /usr/local/bin || exit
 ln -sf ../lib/node_modules/npm/bin/npm-cli.js npm
 ln -sf ../lib/node_modules/npm/bin/npx-cli.js npx
diff --git a/tools/rpm/rpmbuild.sh b/tools/rpm/rpmbuild.sh
index 6f2d0d123be..6c990c8e94b 100755
--- a/tools/rpm/rpmbuild.sh
+++ b/tools/rpm/rpmbuild.sh
@@ -16,7 +16,7 @@
 
 set -e
 
-TOOLSDIR=`dirname $0`
+TOOLSDIR=`dirname "$0"`
 TOPLEVELDIR="$TOOLSDIR/../.."
 
 RPMBUILD_PATH="${RPMBUILD_PATH:-$HOME/rpmbuild}"
@@ -38,7 +38,7 @@ fi
 set -x
 
 sed -re "s/%define _version .+/%define _version ${VERSION}/" \
-    "$TOOLSDIR/node.spec" > $RPMBUILD_PATH/SPECS/node.spec
+    "$TOOLSDIR/node.spec" > "$RPMBUILD_PATH/SPECS/node.spec"
 tar --exclude-vcs --transform="s|^|node-${VERSION}/|" \
-    -czf $RPMBUILD_PATH/SOURCES/node-v${VERSION}.tar.gz .
-rpmbuild $* -ba $RPMBUILD_PATH/SPECS/node.spec
+    -czf "$RPMBUILD_PATH/SOURCES/node-v${VERSION}.tar.gz" .
+rpmbuild "$*" -ba "$RPMBUILD_PATH/SPECS/node.spec"
diff --git a/tools/update-eslint.sh b/tools/update-eslint.sh
index f877c0a9e48..f3e43ae31d2 100755
--- a/tools/update-eslint.sh
+++ b/tools/update-eslint.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 
 # Shell script to update ESLint in the source tree to the latest release.
 
@@ -7,24 +7,28 @@
 # This script must be be in the tools directory when it runs because it uses
 # $BASH_SOURCE[0] to determine directories to work in.
 
-cd "$( dirname "${BASH_SOURCE[0]}" )"
+cd "$( dirname "$0" )" || exit
 rm -rf node_modules/eslint
-mkdir eslint-tmp
-cd eslint-tmp
-npm init --yes
+{
+    mkdir eslint-tmp
+    cd eslint-tmp || exit
+    npm init --yes
 
-npm install --global-style --no-bin-links --production --no-package-lock eslint@latest
-cd node_modules/eslint
+    npm install --global-style --no-bin-links --production --no-package-lock eslint@latest
 
-npm install --no-bin-links --production --no-package-lock eslint-plugin-markdown@latest
-cd ../..
+    {
+        cd node_modules/eslint || exit
 
-# Use dmn to remove some unneeded files.
-npx dmn@2.2.2 -f clean
-# Use removeNPMAbsolutePaths to remove unused data in package.json.
-# This avoids churn as absolute paths can change from one dev to another.
-npx removeNPMAbsolutePaths@1.0.4 .
+        npm install --no-bin-links --production --no-package-lock eslint-plugin-markdown@latest
+    }
+
+
+    # Use dmn to remove some unneeded files.
+    npx dmn@2.2.2 -f clean
+    # Use removeNPMAbsolutePaths to remove unused data in package.json.
+    # This avoids churn as absolute paths can change from one dev to another.
+    npx removeNPMAbsolutePaths@1.0.4 .
+}
 
-cd ..
 mv eslint-tmp/node_modules/eslint node_modules/eslint
 rm -rf eslint-tmp/
diff --git a/tools/update-npm.sh b/tools/update-npm.sh
index 5865f7d4e8c..c106570d0b3 100755
--- a/tools/update-npm.sh
+++ b/tools/update-npm.sh
@@ -1,4 +1,4 @@
-#!/usr/bin/env bash
+#!/bin/sh
 set -e
 # Shell script to update npm in the source tree to a specific version