diff --git a/newspack-sacha/template-parts/post/author-bio.php b/newspack-sacha/template-parts/post/author-bio.php
index 406011f02..108c5eaa7 100644
--- a/newspack-sacha/template-parts/post/author-bio.php
+++ b/newspack-sacha/template-parts/post/author-bio.php
@@ -11,6 +11,8 @@
 }
 
 $author_bio_length = get_theme_mod( 'author_bio_length', 200 );
+// Shared avatar image size for author archive + author bio templates.
+$author_avatar_size = get_theme_mod( 'author_avatar_size', 120 );
 
 if ( function_exists( 'coauthors_posts_links' ) && is_single() && ! empty( get_coauthors() ) ) : // phpcs:ignore PHPCompatibility.LanguageConstructs.NewEmptyNonVariable.Found
 
@@ -20,7 +22,7 @@
 
 		if ( '' !== $author->description ) {
 			// avatar_img_tag is a property added by Newspack Network plugin to distributed posts.
-			$author_avatar = $author->avatar_img_tag ?? coauthors_get_avatar( $author, 80 );
+			$author_avatar = $author->avatar_img_tag ?? coauthors_get_avatar( $author, absint( $author_avatar_size ) );
 			$author_url    = get_author_posts_url( $author->ID, $author->user_nicename );
 
 			/**
@@ -109,7 +111,7 @@
 	<div class="author-bio-text">
 		<div class="author-bio-header">
 			<?php
-				$author_avatar = get_avatar( get_the_author_meta( 'ID' ), 80 );
+				$author_avatar = get_avatar( get_the_author_meta( 'ID' ), absint( $author_avatar_size ) );
 			if ( $author_avatar ) {
 				?>
 				<a href="<?php echo esc_url( get_author_posts_url( get_the_author_meta( 'ID' ) ) ); ?>" rel="author">
diff --git a/newspack-theme/archive.php b/newspack-theme/archive.php
index 8c4b7b271..eb6ea1c33 100755
--- a/newspack-theme/archive.php
+++ b/newspack-theme/archive.php
@@ -17,6 +17,8 @@
 
 $feature_latest_post = get_theme_mod( 'archive_feature_latest_post', true );
 $show_excerpt        = get_theme_mod( 'archive_show_excerpt', false );
+// Shared avatar image size for author archive + author bio templates.
+$author_avatar_size = get_theme_mod( 'author_avatar_size', 120 );
 
 // Hide author on collection category archives.
 if ( class_exists( '\Newspack\Optional_Modules\Collections' ) &&
@@ -35,10 +37,10 @@
 				$author_avatar = '';
 
 				if ( function_exists( 'coauthors_posts_links' ) ) {
-					$author_avatar = coauthors_get_avatar( $queried, 120 );
+					$author_avatar = coauthors_get_avatar( $queried, absint( $author_avatar_size ) );
 				} else {
 					$author_id     = get_query_var( 'author' );
-					$author_avatar = get_avatar( $author_id, 120 );
+					$author_avatar = get_avatar( $author_id, absint( $author_avatar_size ) );
 				}
 
 				if ( $author_avatar ) {
diff --git a/newspack-theme/inc/customizer.php b/newspack-theme/inc/customizer.php
index 76ccf7d32..ca1a7c8ce 100755
--- a/newspack-theme/inc/customizer.php
+++ b/newspack-theme/inc/customizer.php
@@ -823,6 +823,29 @@ function newspack_customize_register( $wp_customize ) {
 		)
 	);
 
+	// Shared avatar image size for author archive and author bio templates.
+	$wp_customize->add_setting(
+		'author_avatar_size',
+		array(
+			'default'           => 120,
+			'sanitize_callback' => 'newspack_sanitize_author_avatar_size',
+		)
+	);
+	$wp_customize->add_control(
+		'author_avatar_size',
+		array(
+			'type'        => 'number',
+			'label'       => esc_html__( 'Author Avatar Size', 'newspack-theme' ),
+			'description' => esc_html__( 'One shared setting for author archive and author bio avatars. Values are saved in the 32-512px range. This controls the requested image size; final on-screen size is still controlled by CSS.', 'newspack-theme' ),
+			'input_attrs' => array(
+				'min'  => 32,
+				'max'  => 512,
+				'step' => 1,
+			),
+			'section'     => 'author_bio_options',
+		)
+	);
+
 	/**
 	 * Template Settings
 	 */
@@ -1692,6 +1715,27 @@ function newspack_sanitize_checkbox( $input ) {
 	}
 }
 
+/**
+ * Sanitize author avatar image size.
+ *
+ * @param int|string $input Requested avatar size.
+ *
+ * @return int Clamped avatar size.
+ */
+function newspack_sanitize_author_avatar_size( $input ) {
+	$size = absint( $input );
+
+	if ( $size < 32 ) {
+		return 32;
+	}
+
+	if ( $size > 512 ) {
+		return 512;
+	}
+
+	return $size;
+}
+
 /**
  * Sanitize the radio buttons.
  */
diff --git a/newspack-theme/template-parts/post/author-bio.php b/newspack-theme/template-parts/post/author-bio.php
index eeb5c171b..46493e73d 100755
--- a/newspack-theme/template-parts/post/author-bio.php
+++ b/newspack-theme/template-parts/post/author-bio.php
@@ -11,6 +11,8 @@
 }
 
 $author_bio_length = get_theme_mod( 'author_bio_length', 200 );
+// Shared avatar image size for author archive + author bio templates.
+$author_avatar_size = get_theme_mod( 'author_avatar_size', 120 );
 
 if ( function_exists( 'coauthors_posts_links' ) && is_single() && ! empty( get_coauthors() ) ) : // phpcs:ignore PHPCompatibility.LanguageConstructs.NewEmptyNonVariable.Found
 
@@ -20,7 +22,7 @@
 
 		if ( '' !== $author->description ) {
 			// avatar_img_tag is a property added by Newspack Network plugin to distributed posts.
-			$author_avatar = $author->avatar_img_tag ?? coauthors_get_avatar( $author, 80 );
+			$author_avatar = $author->avatar_img_tag ?? coauthors_get_avatar( $author, absint( $author_avatar_size ) );
 			$author_url    = get_author_posts_url( $author->ID, $author->user_nicename );
 
 			/**
@@ -113,7 +115,7 @@
 	}
 
 elseif ( (bool) get_the_author_meta( 'description' ) && is_single() ) :
-	$author_avatar = get_avatar( get_the_author_meta( 'ID' ), 80 );
+	$author_avatar = get_avatar( get_the_author_meta( 'ID' ), absint( $author_avatar_size ) );
 	?>
 
 <div class="author-bio">