diff --git a/author.php b/author.php
index c1abdf757d..8397c618fc 100755
--- a/author.php
+++ b/author.php
@@ -30,7 +30,7 @@
     $context['og_title'] = $author->name;
     $context['og_description'] = get_the_author_meta('description', $author->ID);
     $context['og_image_data'] = [
-        'url' => get_avatar_url($author->ID, [ 'size' => 300 ]),
+        'url' => get_avatar_url($author->ID, [ 'size' => 300, 'default' => $context['default_avatar']]),
         'width' => '300',
         'height' => '300',
     ];
diff --git a/images/p4-avatar.jpg b/images/p4-avatar.jpg
new file mode 100644
index 0000000000..24e6ff6e1c
Binary files /dev/null and b/images/p4-avatar.jpg differ
diff --git a/src/MasterSite.php b/src/MasterSite.php
index 37b991320a..81c78dc84b 100644
--- a/src/MasterSite.php
+++ b/src/MasterSite.php
@@ -762,6 +762,14 @@ function ($item) {
         // IA: Tabs menu on mobile.
         $context['mobile_tabs_menu'] = (bool) planet4_get_option('new_ia');
 
+        // Default avatar.
+        if (defined('WP_DEBUG') && WP_DEBUG === true) {
+            // Gravatar throws an error for local dev default_avatar URL, so the default value is used.
+            $context['default_avatar'] = 'mm'; //Mystery Man
+        } else {
+            $context['default_avatar'] = get_template_directory_uri() . '/images/p4-avatar.jpg';
+        }
+
         return $context;
     }
 
diff --git a/templates/author.twig b/templates/author.twig
index f203053c36..b2af9b03ab 100644
--- a/templates/author.twig
+++ b/templates/author.twig
@@ -5,7 +5,7 @@
         {% if ( author.avatar ) %}
             <figure class="author-image" aria-label="{{ __( 'Picture of ' ~ author.name , 'planet4-master-theme' ) }}">
                 <img itemprop="image" class="author-pic"
-                     src="{{ fn('get_avatar_url', author.id, {'size' : 300}) | replace({'=s96-c':""}) }}"
+                     src="{{ fn('get_avatar_url', author.id, {'size' : 300, 'default': default_avatar}) | replace({'=s96-c':""}) }}"
                      alt="{{ author.name }}">
             </figure>
         {% endif %}
diff --git a/templates/blocks/author_profile.twig b/templates/blocks/author_profile.twig
index c819761b8a..b8f6ff99f8 100644
--- a/templates/blocks/author_profile.twig
+++ b/templates/blocks/author_profile.twig
@@ -5,7 +5,7 @@
                 <figure class="author-block-image d-none d-sm-none d-md-block">
                     <img
                         itemprop="image"
-                        src="{{ fn('get_avatar_url', post.author.id, {'size' : 294 }) | replace({'=s96-c':""}) }}"
+                        src="{{ fn('get_avatar_url', post.author.id, {'size' : 294, 'default': default_avatar}) | replace({'=s96-c':""}) }}"
                         alt="{{ post.author.name }}"
                     />
                 </figure>
@@ -16,7 +16,7 @@
                     <figure class="author-block-image d-block d-sm-block d-md-none">
                         <img
                             itemprop="image"
-                            src="{{ fn('get_avatar_url', post.author.id, {'size' : 294 }) | replace({'=s96-c':""}) }}"
+                            src="{{ fn('get_avatar_url', post.author.id, {'size' : 294, 'default': default_avatar}) | replace({'=s96-c':""}) }}"
                             alt="{{ post.author.name }}"
                         />
                     </figure>
diff --git a/templates/single.twig b/templates/single.twig
index fe1f62adff..5a5d992ef7 100644
--- a/templates/single.twig
+++ b/templates/single.twig
@@ -48,7 +48,7 @@
                 <div class="single-post-meta">
                     {% if not post.get_author_override and post.author.avatar %}
                         <img itemprop="image" class="author-pic"
-                            src="{{ fn('get_avatar_url', post.author.id, {'size' : 50, 'default': 'mm'}) }}"
+                            src="{{ fn('get_avatar_url', post.author.id, {'size' : 50, 'default': default_avatar}) }}"
                             alt="{{ post.author.avatar }}">
                     {% endif %}
                     <div class="d-inline-block">