diff --git a/.github/workflows/release-binaries.yml b/.github/workflows/release-binaries.yml
index 122550d..51fb8b6 100644
--- a/.github/workflows/release-binaries.yml
+++ b/.github/workflows/release-binaries.yml
@@ -17,8 +17,8 @@ concurrency:
 jobs:
 
   release:
-    runs-on: ubuntu-latest
-    timeout-minutes: 10
+    runs-on: macos-latest
+    timeout-minutes: 30
 
     steps:
       - name: Checkout Repository
@@ -73,6 +73,30 @@ jobs:
           GOOS=darwin GOARCH=amd64 go build -trimpath -o dist/embed-code-macos main.go
           chmod +x dist/embed-code-linux dist/embed-code-macos
 
+      # Sign the macOS binary with a Developer ID certificate stored in GitHub
+      # secrets. The certificate must be exported as a base64-encoded .p12 file.
+      - name: Sign macOS Binary
+        if: steps.release.outputs.publish == 'true'
+        shell: bash
+        env:
+          MACOS_CERTIFICATE_P12_BASE64: ${{ secrets.MACOS_CERTIFICATE_P12_BASE64 }}
+          MACOS_CERTIFICATE_PASSWORD: ${{ secrets.MACOS_CERTIFICATE_PASSWORD }}
+          MACOS_CODESIGN_IDENTITY: ${{ secrets.MACOS_CODESIGN_IDENTITY }}
+        run: |
+          scripts/release/sign-macos-binary.sh dist/embed-code-macos
+
+      # Notarize the macOS ZIP that will be published as the release asset.
+      - name: Notarize macOS Binary
+        if: steps.release.outputs.publish == 'true'
+        shell: bash
+        env:
+          APPLE_ID: ${{ secrets.APPLE_ID }}
+          APPLE_TEAM_ID: ${{ secrets.APPLE_TEAM_ID }}
+          APPLE_APP_SPECIFIC_PASSWORD: ${{ secrets.APPLE_APP_SPECIFIC_PASSWORD }}
+        run: |
+          scripts/release/notarize-macos-zip.sh dist/embed-code-macos dist/embed-code-macos.zip
+          rm dist/embed-code-macos
+
       # Create the release for the current commit and attach all generated binaries.
       - name: Publish GitHub Release
         if: steps.release.outputs.publish == 'true'
diff --git a/PROJECT.md b/PROJECT.md
index f2076c5..fc120d9 100644
--- a/PROJECT.md
+++ b/PROJECT.md
@@ -30,6 +30,8 @@ them inside code fences, and checks whether existing snippets are up-to-date.
 - `type/`: YAML-compatible string and named-path list types. The import path
   segment is `type`, but the Go package identifier is `_type` because `type` is
   a Go keyword.
+- `scripts/release/`: helper scripts used by release workflows for signing and
+  notarizing macOS binaries.
 - `test/resources/`: parser, embedding, configuration, and source-code fixtures.
 - `showcase/`: executable user guide and end-to-end example suite.
 
@@ -56,7 +58,8 @@ This repository is configured with these GitHub workflows:
 - `check`: runs linting, the normal Go test suite, and the showcase end-to-end
   tests across supported platforms.
 - `release-binaries`: reads `VERSION`, builds Linux, macOS, and Windows
-  binaries, and creates the matching GitHub Release on pushes to `master`.
+  binaries, signs and notarizes the macOS ZIP, and creates the matching GitHub
+  Release on pushes to `master`.
 
 The release tag is `v<version>` from `VERSION`. When the release already exists,
 the workflow emits a warning and finishes successfully without rebuilding or
diff --git a/README.md b/README.md
index 7f070e0..d20fac6 100644
--- a/README.md
+++ b/README.md
@@ -36,11 +36,12 @@ On Linux, for example:
 > chmod +x embed-code-linux
 > ```
 
-> Since binary file for macOS is not signed, it may be necessary 
-> to change its attributes to allow execution:
-> ```bash
-> xattr -d com.apple.quarantine embed-code-macos
-> ```
+On macOS, download `embed-code-macos.zip`, unzip it, and run the binary:
+
+```bash
+unzip embed-code-macos.zip
+./embed-code-macos -mode=check -config-path=showcase/embedding/embed-code.yml
+```
 
 Or run it with Go:
 
diff --git a/scripts/release/README.md b/scripts/release/README.md
new file mode 100644
index 0000000..3755ffb
--- /dev/null
+++ b/scripts/release/README.md
@@ -0,0 +1,47 @@
+# Release Scripts
+
+These scripts support the `release-binaries` GitHub workflow. 
+They are intended for the macOS release job.
+
+## Signing
+
+Use `sign-macos-binary.sh` to import the Developer ID certificate into a
+temporary keychain and sign the macOS binary.
+
+Required environment variables:
+
+- `MACOS_CERTIFICATE_P12_BASE64`: base64-encoded `.p12` export of the Developer
+  ID Application certificate and private key.
+- `MACOS_CERTIFICATE_PASSWORD`: password used when exporting the `.p12` file.
+- `MACOS_CODESIGN_IDENTITY`: full Developer ID Application identity, such as
+  `Developer ID Application: Company Name (TEAMID)`.
+
+Optional environment variable:
+
+- `MACOS_KEYCHAIN_PASSWORD`: password for the temporary keychain. When omitted,
+  the script generates one.
+
+Example:
+
+```bash
+scripts/release/sign-macos-binary.sh dist/embed-code-macos
+```
+
+## Notarization
+
+Use `notarize-macos-zip.sh` to package the signed CLI binary as a ZIP archive
+and submit that archive to Apple notarization.
+
+Required environment variables:
+
+- `APPLE_ID`: Apple Account email used for notarization.
+- `APPLE_TEAM_ID`: 10-character Apple Developer Team ID.
+- `APPLE_APP_SPECIFIC_PASSWORD`: app-specific password for the Apple Account.
+
+Example:
+
+```bash
+scripts/release/notarize-macos-zip.sh \
+  dist/embed-code-macos \
+  dist/embed-code-macos.zip
+```
diff --git a/scripts/release/notarize-macos-zip.sh b/scripts/release/notarize-macos-zip.sh
new file mode 100755
index 0000000..957050e
--- /dev/null
+++ b/scripts/release/notarize-macos-zip.sh
@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+
+# Packages and notarizes the signed macOS CLI binary.
+#
+# Usage:
+#   scripts/release/notarize-macos-zip.sh \
+#     dist/embed-code-macos \
+#     dist/embed-code-macos.zip
+#
+# The script expects these environment variables:
+#   APPLE_ID
+#   APPLE_TEAM_ID
+#   APPLE_APP_SPECIFIC_PASSWORD
+#
+# Apple notarization accepts an archive/package submission, so the CLI binary is
+# wrapped in a ZIP instead of being uploaded as a loose executable.
+#
+# The script writes the ZIP path passed as its second argument and waits for
+# Apple to accept or reject the notarization submission.
+set -euo pipefail
+
+# Verifies, that secrets are set.
+required_vars=(
+  APPLE_ID
+  APPLE_TEAM_ID
+  APPLE_APP_SPECIFIC_PASSWORD
+)
+
+missing=()
+for var_name in "${required_vars[@]}"; do
+  if [[ -z "${!var_name:-}" ]]; then
+    missing+=("$var_name")
+  fi
+done
+if (( ${#missing[@]} > 0 )); then
+  printf 'Missing required environment variable: %s\n' "${missing[@]}" >&2
+  exit 1
+fi
+
+if (( $# != 2 )); then
+  echo "Usage: $0 <signed-macos-binary-path> <zip-output-path>" >&2
+  exit 1
+fi
+
+binary_path="$1"
+zip_path="$2"
+
+if [[ ! -f "$binary_path" ]]; then
+  echo "Signed macOS binary does not exist: $binary_path" >&2
+  exit 1
+fi
+
+binary_dir="$(cd "$(dirname "$binary_path")" && pwd)"
+binary_name="$(basename "$binary_path")"
+zip_dir="$(dirname "$zip_path")"
+zip_name="$(basename "$zip_path")"
+
+# Resolve the ZIP path before changing directories.
+mkdir -p "$zip_dir"
+zip_dir="$(cd "$zip_dir" && pwd)"
+zip_path="$zip_dir/$zip_name"
+
+pushd "$binary_dir" >/dev/null
+ditto -c -k --keepParent "$binary_name" "$zip_path"
+popd >/dev/null
+
+# Wait for the notarization result before publishing.
+# ZIP archives do not support stapling, so the release publishes the accepted archive as-is.
+xcrun notarytool submit "$zip_path" \
+  --apple-id "$APPLE_ID" \
+  --team-id "$APPLE_TEAM_ID" \
+  --password "$APPLE_APP_SPECIFIC_PASSWORD" \
+  --wait
diff --git a/scripts/release/sign-macos-binary.sh b/scripts/release/sign-macos-binary.sh
new file mode 100755
index 0000000..91cebe2
--- /dev/null
+++ b/scripts/release/sign-macos-binary.sh
@@ -0,0 +1,111 @@
+#!/usr/bin/env bash
+
+# Signs the macOS CLI binary with a Developer ID Application certificate.
+#
+# Usage:
+#   scripts/release/sign-macos-binary.sh dist/embed-code-macos
+#
+# The script expects these environment variables:
+#   MACOS_CERTIFICATE_P12_BASE64
+#   MACOS_CERTIFICATE_PASSWORD
+#   MACOS_CODESIGN_IDENTITY
+#
+# The certificate value must be a base64-encoded `.p12` export that contains the
+# Developer ID Application certificate and private key.
+# `MACOS_CODESIGN_IDENTITY` is the full identity printed by
+# `security find-identity`, such as:
+#
+#   Developer ID Application: Company Name (TEAMID)
+#
+# For local diagnostics, `MACOS_KEYCHAIN_PASSWORD` can be set to reuse a known
+# temporary keychain password.
+#
+# The script writes temporary certificate and keychain files under RUNNER_TEMP,
+# or TMPDIR when RUNNER_TEMP is not set. It signs the binary in place and verifies
+# the resulting signature.
+set -euo pipefail
+
+# Verifies, that secrets are set.
+required_vars=(
+  MACOS_CERTIFICATE_P12_BASE64
+  MACOS_CERTIFICATE_PASSWORD
+  MACOS_CODESIGN_IDENTITY
+)
+
+missing=()
+for var_name in "${required_vars[@]}"; do
+  if [[ -z "${!var_name:-}" ]]; then
+    missing+=("$var_name")
+  fi
+done
+if (( ${#missing[@]} > 0 )); then
+  printf 'Missing required environment variable: %s\n' "${missing[@]}" >&2
+  exit 1
+fi
+
+if (( $# != 1 )); then
+  echo "Usage: $0 <macos-binary-path>" >&2
+  exit 1
+fi
+
+binary_path="$1"
+if [[ ! -f "$binary_path" ]]; then
+  echo "macOS binary does not exist: $binary_path" >&2
+  exit 1
+fi
+
+temp_dir="${RUNNER_TEMP:-${TMPDIR:-/tmp}}"
+keychain_path="$temp_dir/embed-code-signing.keychain-db"
+certificate_path="$temp_dir/embed-code-signing-certificate.p12"
+keychain_password="${MACOS_KEYCHAIN_PASSWORD:-$(uuidgen)}"
+
+# Decode the certificate at runtime so only the temporary runner filesystem ever
+# contains the `.p12`.
+if printf '%s' "$MACOS_CERTIFICATE_P12_BASE64" | base64 --decode > "$certificate_path" 2>/dev/null; then
+  :
+else
+  printf '%s' "$MACOS_CERTIFICATE_P12_BASE64" | base64 -D > "$certificate_path"
+fi
+
+security create-keychain -p "$keychain_password" "$keychain_path"
+security set-keychain-settings -lut 21600 "$keychain_path"
+security unlock-keychain -p "$keychain_password" "$keychain_path"
+
+# Import Apple's public certificate chain into the temporary keychain.
+# Some runners do not have the current Developer ID intermediate certificates.
+curl -fsSL https://www.apple.com/certificateauthority/AppleRootCA-G3.cer \
+  -o "$temp_dir/AppleRootCA-G3.cer"
+curl -fsSL https://www.apple.com/certificateauthority/AppleWWDRCAG6.cer \
+  -o "$temp_dir/AppleWWDRCAG6.cer"
+curl -fsSL https://www.apple.com/certificateauthority/DeveloperIDG2CA.cer \
+  -o "$temp_dir/DeveloperIDG2CA.cer"
+
+security import "$temp_dir/AppleRootCA-G3.cer" -k "$keychain_path"
+security import "$temp_dir/AppleWWDRCAG6.cer" -k "$keychain_path"
+security import "$temp_dir/DeveloperIDG2CA.cer" -k "$keychain_path"
+
+# Import the private signing identity and allow Apple signing tools to access
+# the key non-interactively.
+security import "$certificate_path" \
+  -P "$MACOS_CERTIFICATE_PASSWORD" \
+  -A \
+  -t cert \
+  -f pkcs12 \
+  -k "$keychain_path"
+security list-keychains -d user -s "$keychain_path"
+security set-key-partition-list \
+  -S apple-tool:,apple: \
+  -s \
+  -k "$keychain_password" \
+  "$keychain_path"
+security find-identity -v -p codesigning "$keychain_path"
+
+# Use the hardened runtime and a trusted timestamp so Gatekeeper can evaluate
+# the signature after the Developer ID certificate eventually expires.
+codesign \
+  --force \
+  --options runtime \
+  --timestamp \
+  --sign "$MACOS_CODESIGN_IDENTITY" \
+  "$binary_path"
+codesign --verify --verbose=4 "$binary_path"