diff --git a/includes/class-micropub.php b/includes/class-micropub.php
index 1006003..d5b9dca 100644
--- a/includes/class-micropub.php
+++ b/includes/class-micropub.php
@@ -32,6 +32,13 @@ class Micropub {
 	 */
 	const TEXT_DOMAIN = 'micropub';
 
+	/**
+	 * Option name for storing microformats2 theme support detection.
+	 *
+	 * @var string
+	 */
+	const MICROFORMATS2_SUPPORT_OPTION = 'micropub_theme_supports_mf2';
+
 	/**
 	 * Get the instance of the class.
 	 *
@@ -59,6 +66,9 @@ public function init() {
 		\add_action( 'rest_api_init', array( $this, 'rest_init' ) );
 		\add_action( 'init', array( $this, 'plugin_init' ) );
 		\add_action( 'admin_notices', array( $this, 'ssl_notice' ) );
+
+		// Clear microformats2 support cache when theme changes.
+		\add_action( 'switch_theme', array( $this, 'clear_microformats2_support_cache' ) );
 	}
 
 	/**
@@ -102,4 +112,77 @@ public function ssl_notice() {
 		</div>
 		<?php
 	}
+
+	/**
+	 * Clear the cached microformats2 support detection.
+	 */
+	public function clear_microformats2_support_cache() {
+		\delete_option( self::MICROFORMATS2_SUPPORT_OPTION );
+	}
+
+	/**
+	 * Check if the current theme supports microformats2.
+	 *
+	 * This checks explicit theme support first, then falls back to
+	 * cached detection results. If no cached result exists and we're
+	 * on a singular page, it will detect and cache the result.
+	 *
+	 * @return bool True if theme supports microformats2.
+	 */
+	public static function theme_supports_microformats2() {
+		// First check explicit theme support declaration.
+		if ( \current_theme_supports( 'microformats2' ) ) {
+			return true;
+		}
+
+		// Check cached detection result.
+		$cached = \get_option( self::MICROFORMATS2_SUPPORT_OPTION );
+
+		if ( false !== $cached ) {
+			return 'yes' === $cached;
+		}
+
+		// If we're on a singular frontend page, detect and cache the result.
+		if ( ! \is_admin() && \is_singular() ) {
+			// Hook into shutdown to check the rendered output, but avoid adding multiple times.
+			if ( ! \has_action( 'shutdown', array( self::class, 'detect_microformats2_support' ) ) ) {
+				\add_action( 'shutdown', array( self::class, 'detect_microformats2_support' ), 0 );
+			}
+		}
+
+		// Return false for now, will be cached after first detection.
+		return false;
+	}
+
+	/**
+	 * Detect microformats2 support by checking the rendered page output.
+	 *
+	 * This runs at shutdown to capture the full page HTML and check
+	 * if e-content class exists in the template markup.
+	 *
+	 * The detection result is stored in a persistent option that survives
+	 * across requests. This cached value is reused by theme_supports_microformats2()
+	 * on subsequent requests and is only cleared when the theme is switched.
+	 */
+	public static function detect_microformats2_support() {
+		$output = \ob_get_contents();
+
+		if ( empty( $output ) ) {
+			return;
+		}
+
+		// Remove code and pre blocks to avoid false positives from user content.
+		$filtered = preg_replace( '/<(code|pre)[^>]*>.*?<\/\1>/is', '', $output );
+
+		// If the regex fails, abort detection to avoid incorrect caching.
+		if ( null === $filtered ) {
+			return;
+		}
+
+		// Check if e-content exists as a class attribute value.
+		// Matches class="...e-content..." or class='...e-content...'.
+		$has_support = preg_match( '/class=["\'][^"\']*\be-content\b[^"\']*["\']/', $filtered );
+
+		\update_option( self::MICROFORMATS2_SUPPORT_OPTION, $has_support ? 'yes' : 'no', false );
+	}
 }
diff --git a/includes/class-render.php b/includes/class-render.php
index 4bc8f98..1d17804 100644
--- a/includes/class-render.php
+++ b/includes/class-render.php
@@ -159,9 +159,15 @@ public static function generate_post_content( $post_content, $input ) {
 		}
 
 		if ( ! empty( $post_content ) ) {
-			$lines[] = '<div class="e-content">';
+			// Only wrap in e-content if theme doesn't already provide microformats2 support.
+			$wrap_econtent = ! Micropub::theme_supports_microformats2();
+			if ( $wrap_econtent ) {
+				$lines[] = '<div class="e-content">';
+			}
 			$lines[] = $post_content;
-			$lines[] = '</div>';
+			if ( $wrap_econtent ) {
+				$lines[] = '</div>';
+			}
 		}
 
 		// Generate gallery markup for media fields.
diff --git a/tests/test_functions.php b/tests/test_functions.php
index 673b895..07a8962 100644
--- a/tests/test_functions.php
+++ b/tests/test_functions.php
@@ -27,3 +27,92 @@ function test_mp_filter() {
 		);
 	}
 }
+
+class MicropubMicroformats2DetectionTest extends WP_UnitTestCase {
+	function tear_down() {
+		// Clean up after each test.
+		remove_theme_support( 'microformats2' );
+		delete_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION );
+		parent::tear_down();
+	}
+
+	function test_theme_supports_microformats2_with_explicit_support() {
+		add_theme_support( 'microformats2' );
+
+		$this->assertTrue( \Micropub\Micropub::theme_supports_microformats2() );
+	}
+
+	function test_theme_supports_microformats2_with_cached_yes() {
+		update_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION, 'yes' );
+
+		$this->assertTrue( \Micropub\Micropub::theme_supports_microformats2() );
+	}
+
+	function test_theme_supports_microformats2_with_cached_no() {
+		update_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION, 'no' );
+
+		$this->assertFalse( \Micropub\Micropub::theme_supports_microformats2() );
+	}
+
+	function test_theme_supports_microformats2_returns_false_when_not_cached() {
+		// No theme support and no cached value.
+		$this->assertFalse( \Micropub\Micropub::theme_supports_microformats2() );
+	}
+
+	function test_clear_microformats2_support_cache() {
+		update_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION, 'yes' );
+
+		$micropub = \Micropub\Micropub::get_instance();
+		$micropub->clear_microformats2_support_cache();
+
+		$this->assertFalse( get_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION ) );
+	}
+
+	function test_detect_microformats2_support_finds_econtent_in_class() {
+		// Start output buffering to simulate page output.
+		ob_start();
+		echo '<html><body><div class="entry-content e-content">Test</div></body></html>';
+
+		\Micropub\Micropub::detect_microformats2_support();
+
+		ob_end_clean();
+
+		$this->assertEquals( 'yes', get_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION ) );
+	}
+
+	function test_detect_microformats2_support_ignores_econtent_in_code_blocks() {
+		// Start output buffering to simulate page output.
+		ob_start();
+		echo '<html><body><code>class="e-content"</code></body></html>';
+
+		\Micropub\Micropub::detect_microformats2_support();
+
+		ob_end_clean();
+
+		$this->assertEquals( 'no', get_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION ) );
+	}
+
+	function test_detect_microformats2_support_ignores_econtent_in_pre_blocks() {
+		// Start output buffering to simulate page output.
+		ob_start();
+		echo '<html><body><pre>class="e-content"</pre></body></html>';
+
+		\Micropub\Micropub::detect_microformats2_support();
+
+		ob_end_clean();
+
+		$this->assertEquals( 'no', get_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION ) );
+	}
+
+	function test_detect_microformats2_support_ignores_econtent_as_plain_text() {
+		// Start output buffering to simulate page output.
+		ob_start();
+		echo '<html><body><p>The e-content class is used in microformats2.</p></body></html>';
+
+		\Micropub\Micropub::detect_microformats2_support();
+
+		ob_end_clean();
+
+		$this->assertEquals( 'no', get_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION ) );
+	}
+}
diff --git a/tests/test_render.php b/tests/test_render.php
index 780bc8d..7102666 100644
--- a/tests/test_render.php
+++ b/tests/test_render.php
@@ -218,4 +218,61 @@ function test_merges_auto_generated_content() {
 			$post_content
 		);
 	}
+
+	function test_no_econtent_wrapper_when_theme_supports_microformats2() {
+		// Simulate theme support for microformats2.
+		add_theme_support( 'microformats2' );
+
+		$content      = '<p>Test content</p>';
+		$input        = array(
+			'properties' => array(
+				'content' => array( $content ),
+			),
+		);
+		$post_content = \Micropub\Render::generate_post_content( $content, $input );
+
+		// Should not have e-content wrapper.
+		$this->assertEquals( '<p>Test content</p>', $post_content );
+
+		// Clean up.
+		remove_theme_support( 'microformats2' );
+	}
+
+	function test_econtent_wrapper_when_theme_does_not_support_microformats2() {
+		// Ensure no theme support.
+		remove_theme_support( 'microformats2' );
+		// Clear any cached detection.
+		delete_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION );
+
+		$content      = '<p>Test content</p>';
+		$input        = array(
+			'properties' => array(
+				'content' => array( $content ),
+			),
+		);
+		$post_content = \Micropub\Render::generate_post_content( $content, $input );
+
+		// Should have e-content wrapper.
+		$this->assertEquals( "<div class=\"e-content\">\n<p>Test content</p>\n</div>", $post_content );
+	}
+
+	function test_no_econtent_wrapper_with_cached_mf2_support() {
+		// Simulate cached detection of microformats2 support.
+		remove_theme_support( 'microformats2' );
+		update_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION, 'yes' );
+
+		$content      = '<p>Test content</p>';
+		$input        = array(
+			'properties' => array(
+				'content' => array( $content ),
+			),
+		);
+		$post_content = \Micropub\Render::generate_post_content( $content, $input );
+
+		// Should not have e-content wrapper due to cached support.
+		$this->assertEquals( '<p>Test content</p>', $post_content );
+
+		// Clean up.
+		delete_option( \Micropub\Micropub::MICROFORMATS2_SUPPORT_OPTION );
+	}
 }