diff --git a/composer.json b/composer.json
index d12c0bbc..ebc117cc 100644
--- a/composer.json
+++ b/composer.json
@@ -57,6 +57,7 @@
             "plugin search",
             "plugin status",
             "plugin check-update",
+            "plugin download",
             "plugin toggle",
             "plugin uninstall",
             "plugin update",
@@ -82,6 +83,7 @@
             "theme search",
             "theme status",
             "theme check-update",
+            "theme download",
             "theme update",
             "theme mod list",
             "theme auto-updates",
diff --git a/extension-command.php b/extension-command.php
index 3cc65c80..f42d46ee 100644
--- a/extension-command.php
+++ b/extension-command.php
@@ -8,6 +8,8 @@
 if ( file_exists( $wpcli_extension_autoloader ) ) {
 	require_once $wpcli_extension_autoloader;
 }
+require_once __DIR__ . '/src/Plugin_Download_Command.php';
+require_once __DIR__ . '/src/Theme_Download_Command.php';
 
 $wpcli_extension_requires_wp_5_5 = [
 	'before_invoke' => static function () {
@@ -18,8 +20,10 @@
 ];
 
 WP_CLI::add_command( 'plugin', 'Plugin_Command' );
+WP_CLI::add_command( 'plugin download', 'Plugin_Download_Command' );
 WP_CLI::add_command( 'plugin auto-updates', 'Plugin_AutoUpdates_Command', $wpcli_extension_requires_wp_5_5 );
 WP_CLI::add_command( 'theme', 'Theme_Command' );
+WP_CLI::add_command( 'theme download', 'Theme_Download_Command' );
 WP_CLI::add_command( 'theme auto-updates', 'Theme_AutoUpdates_Command', $wpcli_extension_requires_wp_5_5 );
 WP_CLI::add_command( 'theme mod', 'Theme_Mod_Command' );
 
diff --git a/features/extension-download.feature b/features/extension-download.feature
new file mode 100644
index 00000000..f05f5eef
--- /dev/null
+++ b/features/extension-download.feature
@@ -0,0 +1,169 @@
+Feature: Download WordPress.org extensions without loading WordPress
+
+  Scenario: Downloading a plugin package works before WordPress is loaded
+    Given an empty directory
+
+    When I run `wp plugin download debug-bar`
+    Then STDOUT should contain:
+      """
+      Downloading debug-bar
+      """
+    And STDOUT should contain:
+      """
+      Success: Downloaded plugin package to
+      """
+    And save STDOUT 'Success: Downloaded plugin package to (.+)' as {DOWNLOADED_PLUGIN}
+    And the {DOWNLOADED_PLUGIN} file should exist
+    And STDERR should be empty
+
+  Scenario: Downloading a plugin package to a custom path
+    Given an empty directory
+
+    When I run `wp plugin download debug-bar --target-path=/tmp/wp-cli-download-test-plugin`
+    Then STDOUT should contain:
+      """
+      Success: Downloaded plugin package to
+      """
+    And save STDOUT 'Success: Downloaded plugin package to (.+)' as {DOWNLOADED_PLUGIN}
+    And the {DOWNLOADED_PLUGIN} file should exist
+    And STDERR should be empty
+
+  Scenario: Downloading a specific version of a plugin
+    Given an empty directory
+
+    When I run `wp plugin download debug-bar --version=1.1`
+    Then STDOUT should contain:
+      """
+      Downloading debug-bar (1.1)
+      """
+    And STDOUT should contain:
+      """
+      Success: Downloaded plugin package to
+      """
+    And STDERR should be empty
+
+  Scenario: Downloading a non-existent version of a plugin fails with clear error
+    Given an empty directory
+
+    When I try `wp plugin download debug-bar --version=9.9.9`
+    Then STDERR should contain:
+      """
+      Error: Can't find the requested plugin's version 9.9.9
+      """
+    And the return code should be 1
+
+  Scenario: Downloading a plugin with --force overwrites existing file
+    Given an empty directory
+
+    When I run `wp plugin download debug-bar`
+    And I run `wp plugin download debug-bar --force`
+    Then STDOUT should contain:
+      """
+      Success: Downloaded plugin package to
+      """
+    And STDERR should be empty
+
+  Scenario: Downloading a plugin without --force fails if destination exists
+    Given an empty directory
+
+    When I run `wp plugin download debug-bar`
+    And I try `wp plugin download debug-bar`
+    Then STDERR should contain:
+      """
+      Error: Destination file already exists:
+      """
+    And the return code should be 1
+
+  Scenario: Downloading an unknown plugin fails with a clear error
+    Given an empty directory
+
+    When I try `wp plugin download this-plugin-does-not-exist-xyz-abc-123`
+    Then STDERR should contain:
+      """
+      Error: The 'this-plugin-does-not-exist-xyz-abc-123' plugin could not be found.
+      """
+    And the return code should be 1
+
+  Scenario: Downloading a theme package works before WordPress is loaded
+    Given an empty directory
+
+    When I run `wp theme download twentytwelve`
+    Then STDOUT should contain:
+      """
+      Downloading twentytwelve
+      """
+    And STDOUT should contain:
+      """
+      Success: Downloaded theme package to
+      """
+    And save STDOUT 'Success: Downloaded theme package to (.+)' as {DOWNLOADED_THEME}
+    And the {DOWNLOADED_THEME} file should exist
+    And STDERR should be empty
+
+  Scenario: Downloading a theme package to a custom path
+    Given an empty directory
+
+    When I run `wp theme download twentytwelve --target-path=/tmp/wp-cli-download-test-theme`
+    Then STDOUT should contain:
+      """
+      Success: Downloaded theme package to
+      """
+    And save STDOUT 'Success: Downloaded theme package to (.+)' as {DOWNLOADED_THEME}
+    And the {DOWNLOADED_THEME} file should exist
+    And STDERR should be empty
+
+  Scenario: Downloading a specific version of a theme
+    Given an empty directory
+
+    When I run `wp theme download twentytwelve --version=1.3`
+    Then STDOUT should contain:
+      """
+      Downloading twentytwelve (1.3)
+      """
+    And STDOUT should contain:
+      """
+      Success: Downloaded theme package to
+      """
+    And STDERR should be empty
+
+  Scenario: Downloading a non-existent version of a theme fails with clear error
+    Given an empty directory
+
+    When I try `wp theme download twentytwelve --version=9.9.9`
+    Then STDERR should contain:
+      """
+      Error: Can't find the requested theme's version 9.9.9
+      """
+    And the return code should be 1
+
+  Scenario: Downloading a theme with --force overwrites existing file
+    Given an empty directory
+
+    When I run `wp theme download twentytwelve`
+    And I run `wp theme download twentytwelve --force`
+    Then STDOUT should contain:
+      """
+      Success: Downloaded theme package to
+      """
+    And STDERR should be empty
+
+  Scenario: Downloading a theme without --force fails if destination exists
+    Given an empty directory
+
+    When I run `wp theme download twentytwelve`
+    And I try `wp theme download twentytwelve`
+    Then STDERR should contain:
+      """
+      Error: Destination file already exists:
+      """
+    And the return code should be 1
+
+  Scenario: Downloading an unknown theme fails with a clear error
+    Given an empty directory
+
+    When I try `wp theme download this-theme-does-not-exist-xyz-abc-123`
+    Then STDERR should contain:
+      """
+      Error: The 'this-theme-does-not-exist-xyz-abc-123' theme could not be found.
+      """
+    And the return code should be 1
diff --git a/phpcs.xml.dist b/phpcs.xml.dist
index 5b3175e3..0a51c466 100644
--- a/phpcs.xml.dist
+++ b/phpcs.xml.dist
@@ -53,7 +53,7 @@
 
 	<!-- Exclude existing classes from the prefix rule as it would break BC to prefix them now. -->
 	<rule ref="WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedClassFound">
-		<exclude-pattern>*/src/(Plugin_(AutoUpdates_)?|Theme_(Mod_|AutoUpdates_)?)Command\.php$</exclude-pattern>
+		<exclude-pattern>*/src/(Plugin_(AutoUpdates_|Download_)?|Theme_(Mod_|AutoUpdates_|Download_)?)Command\.php$</exclude-pattern>
 	</rule>
 
 	<rule ref="WordPress.NamingConventions.PrefixAllGlobals.NonPrefixedNamespaceFound">
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index abaa502d..3b8aeab5 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -7,6 +7,7 @@ parameters:
     - vendor/wp-cli/wp-cli/php
   scanFiles:
     - vendor/php-stubs/wordpress-stubs/wordpress-stubs.php
+    - tests/phpstan/scan-files.php
   treatPhpDocTypesAsCertain: false
   ignoreErrors:
     - identifier: missingType.iterableValue
diff --git a/src/Plugin_Download_Command.php b/src/Plugin_Download_Command.php
new file mode 100644
index 00000000..b3ccb8e5
--- /dev/null
+++ b/src/Plugin_Download_Command.php
@@ -0,0 +1,159 @@
+<?php
+
+use WP_CLI\Utils;
+use WP_CLI\WpOrgApi;
+
+/**
+ * Downloads plugin zip files from the WordPress.org repository.
+ */
+class Plugin_Download_Command {
+
+	/**
+	 * Downloads a plugin zip package without loading WordPress.
+	 *
+	 * ## OPTIONS
+	 *
+	 * <slug>
+	 * : Slug of the plugin to download.
+	 *
+	 * [--target-path=<path>]
+	 * : Directory to store the downloaded zip file. Defaults to the current directory.
+	 *
+	 * [--version=<version>]
+	 * : Version to download. Accepts a version number or `dev`.
+	 *
+	 * [--force]
+	 * : Overwrite destination file if it already exists.
+	 *
+	 * [--insecure]
+	 * : Retry download without certificate validation if TLS handshake fails. Note: This makes the request vulnerable to a MITM attack.
+	 *
+	 * ## EXAMPLES
+	 *
+	 *     $ wp plugin download bbpress
+	 *     Downloading bbpress (2.5.9)...
+	 *     Success: Downloaded plugin package to /path/to/bbpress.2.5.9.zip
+	 *
+	 * @when before_wp_load
+	 *
+	 * @param array{0: string}                                   $args       Positional arguments.
+	 * @param array{target-path?: string, version?: string, force?: bool, insecure?: bool} $assoc_args Associative arguments.
+	 */
+	public function __invoke( $args, $assoc_args ) {
+		$slug = (string) $args[0];
+		if ( '' === trim( $slug ) ) {
+			WP_CLI::error( 'Please provide a plugin slug.' );
+		}
+
+		$insecure     = Utils\get_flag_value( $assoc_args, 'insecure', false );
+		$force        = Utils\get_flag_value( $assoc_args, 'force', false );
+		$requested    = Utils\get_flag_value( $assoc_args, 'version', null );
+		$download_dir = Utils\get_flag_value( $assoc_args, 'target-path', getcwd() ?: '.' );
+
+		if ( ! is_dir( $download_dir ) ) {
+			if ( ! @mkdir( $download_dir, 0755, true ) ) {
+				WP_CLI::error( "Failed to create directory '{$download_dir}'." );
+			}
+		}
+
+		if ( ! is_writable( $download_dir ) ) {
+			WP_CLI::error( "'{$download_dir}' is not writable by current user." );
+		}
+
+		try {
+			$plugin_data = ( new WpOrgApi( [ 'insecure' => $insecure ] ) )->get_plugin_info( $slug );
+		} catch ( Exception $exception ) {
+			WP_CLI::error( "The '{$slug}' plugin could not be found. " . $exception->getMessage() );
+		}
+
+		if ( ! is_array( $plugin_data ) || empty( $plugin_data['download_link'] ) || empty( $plugin_data['version'] ) ) {
+			WP_CLI::error( "The '{$slug}' plugin could not be found." );
+		}
+
+		$download_url = $plugin_data['download_link'];
+		$version      = $plugin_data['version'];
+
+		if ( is_string( $requested ) && '' !== $requested && $requested !== $plugin_data['version'] ) {
+			$current_zip = basename( (string) Utils\parse_url( $download_url, PHP_URL_PATH ) );
+			if ( 'dev' === $requested ) {
+				$download_url = str_replace( $current_zip, $slug . '.zip', $download_url );
+				$version      = 'Development Version';
+			} else {
+				$download_url = str_replace( $current_zip, $slug . '.' . $requested . '.zip', $download_url );
+				$version      = $requested;
+
+				try {
+					$head_response = Utils\http_request( 'HEAD', $download_url, null, [], [ 'insecure' => (bool) $insecure ] );
+				} catch ( Exception $exception ) {
+					WP_CLI::error( $exception->getMessage() );
+				}
+
+				if ( 200 !== (int) $head_response->status_code ) {
+					WP_CLI::error(
+						sprintf(
+							"Can't find the requested plugin's version %s in the WordPress.org plugin repository (HTTP code %d).",
+							$requested,
+							$head_response->status_code
+						)
+					);
+				}
+			}
+		}
+
+		$zip_name = basename( (string) Utils\parse_url( $download_url, PHP_URL_PATH ) );
+		if ( '' === $zip_name ) {
+			$zip_name = "{$slug}.zip";
+		}
+
+		$download_file = rtrim( $download_dir, '/\\' ) . DIRECTORY_SEPARATOR . $zip_name;
+
+		if ( ! $force && file_exists( $download_file ) ) {
+			WP_CLI::error( "Destination file already exists: {$download_file}" );
+		}
+
+		$destination_file = $download_file;
+		$tmp_file         = $download_file;
+
+		if ( $force && file_exists( $destination_file ) ) {
+			$tmp_file = $destination_file . '.tmp.' . uniqid( '', true );
+		}
+
+		WP_CLI::log( "Downloading {$slug} ({$version})..." );
+
+		try {
+			$response = Utils\http_request(
+				'GET',
+				$download_url,
+				null,
+				[],
+				[
+					'filename' => $tmp_file,
+					'insecure' => (bool) $insecure,
+				]
+			);
+		} catch ( Exception $exception ) {
+			if ( file_exists( $tmp_file ) ) {
+				unlink( $tmp_file );
+			}
+			WP_CLI::error( $exception->getMessage() );
+		}
+
+		if ( 200 !== (int) $response->status_code ) {
+			if ( file_exists( $tmp_file ) ) {
+				unlink( $tmp_file );
+			}
+			WP_CLI::error( sprintf( 'Failed to download plugin package (HTTP code %d).', $response->status_code ) );
+		}
+
+		if ( $tmp_file !== $destination_file ) {
+			if ( file_exists( $destination_file ) && ! @unlink( $destination_file ) ) {
+				WP_CLI::error( "Failed to remove existing destination file: {$destination_file}" );
+			}
+			if ( ! @rename( $tmp_file, $destination_file ) ) {
+				WP_CLI::error( "Failed to move downloaded file into place: {$destination_file}" );
+			}
+		}
+
+		WP_CLI::success( "Downloaded plugin package to {$destination_file}" );
+	}
+}
diff --git a/src/Theme_Download_Command.php b/src/Theme_Download_Command.php
new file mode 100644
index 00000000..4d4d5870
--- /dev/null
+++ b/src/Theme_Download_Command.php
@@ -0,0 +1,159 @@
+<?php
+
+use WP_CLI\Utils;
+use WP_CLI\WpOrgApi;
+
+/**
+ * Downloads theme zip files from the WordPress.org repository.
+ */
+class Theme_Download_Command {
+
+	/**
+	 * Downloads a theme zip package without loading WordPress.
+	 *
+	 * ## OPTIONS
+	 *
+	 * <slug>
+	 * : Slug of the theme to download.
+	 *
+	 * [--target-path=<path>]
+	 * : Directory to store the downloaded zip file. Defaults to the current directory.
+	 *
+	 * [--version=<version>]
+	 * : Version to download. Accepts a version number or `dev`.
+	 *
+	 * [--force]
+	 * : Overwrite destination file if it already exists.
+	 *
+	 * [--insecure]
+	 * : Retry download without certificate validation if TLS handshake fails. Note: This makes the request vulnerable to a MITM attack.
+	 *
+	 * ## EXAMPLES
+	 *
+	 *     $ wp theme download twentytwelve
+	 *     Downloading twentytwelve (1.3)...
+	 *     Success: Downloaded theme package to /path/to/twentytwelve.1.3.zip
+	 *
+	 * @when before_wp_load
+	 *
+	 * @param array{0: string}                                   $args       Positional arguments.
+	 * @param array{target-path?: string, version?: string, force?: bool, insecure?: bool} $assoc_args Associative arguments.
+	 */
+	public function __invoke( $args, $assoc_args ) {
+		$slug = (string) $args[0];
+		if ( '' === trim( $slug ) ) {
+			WP_CLI::error( 'Please provide a theme slug.' );
+		}
+
+		$insecure     = Utils\get_flag_value( $assoc_args, 'insecure', false );
+		$force        = Utils\get_flag_value( $assoc_args, 'force', false );
+		$requested    = Utils\get_flag_value( $assoc_args, 'version', null );
+		$download_dir = Utils\get_flag_value( $assoc_args, 'target-path', getcwd() ?: '.' );
+
+		if ( ! is_dir( $download_dir ) ) {
+			if ( ! @mkdir( $download_dir, 0755, true ) ) {
+				WP_CLI::error( "Failed to create directory '{$download_dir}'." );
+			}
+		}
+
+		if ( ! is_writable( $download_dir ) ) {
+			WP_CLI::error( "'{$download_dir}' is not writable by current user." );
+		}
+
+		try {
+			$theme_data = ( new WpOrgApi( [ 'insecure' => $insecure ] ) )->get_theme_info( $slug );
+		} catch ( Exception $exception ) {
+			WP_CLI::error( "The '{$slug}' theme could not be found. " . $exception->getMessage() );
+		}
+
+		if ( ! is_array( $theme_data ) || empty( $theme_data['download_link'] ) || empty( $theme_data['version'] ) ) {
+			WP_CLI::error( "The '{$slug}' theme could not be found." );
+		}
+
+		$download_url = $theme_data['download_link'];
+		$version      = $theme_data['version'];
+
+		if ( is_string( $requested ) && '' !== $requested && $requested !== $theme_data['version'] ) {
+			$current_zip = basename( (string) Utils\parse_url( $download_url, PHP_URL_PATH ) );
+			if ( 'dev' === $requested ) {
+				$download_url = str_replace( $current_zip, $slug . '.zip', $download_url );
+				$version      = 'Development Version';
+			} else {
+				$download_url = str_replace( $current_zip, $slug . '.' . $requested . '.zip', $download_url );
+				$version      = $requested;
+
+				try {
+					$head_response = Utils\http_request( 'HEAD', $download_url, null, [], [ 'insecure' => (bool) $insecure ] );
+				} catch ( Exception $exception ) {
+					WP_CLI::error( $exception->getMessage() );
+				}
+
+				if ( 200 !== (int) $head_response->status_code ) {
+					WP_CLI::error(
+						sprintf(
+							"Can't find the requested theme's version %s in the WordPress.org theme repository (HTTP code %d).",
+							$requested,
+							$head_response->status_code
+						)
+					);
+				}
+			}
+		}
+
+		$zip_name = basename( (string) Utils\parse_url( $download_url, PHP_URL_PATH ) );
+		if ( '' === $zip_name ) {
+			$zip_name = "{$slug}.zip";
+		}
+
+		$download_file = rtrim( $download_dir, '/\\' ) . DIRECTORY_SEPARATOR . $zip_name;
+
+		if ( ! $force && file_exists( $download_file ) ) {
+			WP_CLI::error( "Destination file already exists: {$download_file}" );
+		}
+
+		$destination_file = $download_file;
+		$tmp_file         = $download_file;
+
+		if ( $force && file_exists( $destination_file ) ) {
+			$tmp_file = $destination_file . '.tmp.' . uniqid( '', true );
+		}
+
+		WP_CLI::log( "Downloading {$slug} ({$version})..." );
+
+		try {
+			$response = Utils\http_request(
+				'GET',
+				$download_url,
+				null,
+				[],
+				[
+					'filename' => $tmp_file,
+					'insecure' => (bool) $insecure,
+				]
+			);
+		} catch ( Exception $exception ) {
+			if ( file_exists( $tmp_file ) ) {
+				unlink( $tmp_file );
+			}
+			WP_CLI::error( $exception->getMessage() );
+		}
+
+		if ( 200 !== (int) $response->status_code ) {
+			if ( file_exists( $tmp_file ) ) {
+				unlink( $tmp_file );
+			}
+			WP_CLI::error( sprintf( 'Failed to download theme package (HTTP code %d).', $response->status_code ) );
+		}
+
+		if ( $tmp_file !== $destination_file ) {
+			if ( file_exists( $destination_file ) && ! @unlink( $destination_file ) ) {
+				WP_CLI::error( "Failed to remove existing destination file: {$destination_file}" );
+			}
+			if ( ! @rename( $tmp_file, $destination_file ) ) {
+				WP_CLI::error( "Failed to move downloaded file into place: {$destination_file}" );
+			}
+		}
+
+		WP_CLI::success( "Downloaded theme package to {$destination_file}" );
+	}
+}
diff --git a/tests/phpstan/scan-files.php b/tests/phpstan/scan-files.php
new file mode 100644
index 00000000..f6f5525f
--- /dev/null
+++ b/tests/phpstan/scan-files.php
@@ -0,0 +1,14 @@
+<?php
+// phpcs:ignoreFile
+
+namespace {
+
+	class Requests_Response {
+		/** @var bool */
+		public $success;
+		/** @var int */
+		public $status_code;
+		/** @var string */
+		public $body;
+	}
+}