diff --git a/src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss b/src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss
index c02df47d5605c..0763a58a106c6 100644
--- a/src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss
+++ b/src/wp-content/themes/twentynineteen/sass/blocks/_blocks.scss
@@ -747,6 +747,10 @@
 			}
 		}
 
+		&.alignfull:not(.is-style-dots) {
+			max-width: none;
+		}
+
 		/* Remove duplicate rule-line when a separator
 		 * is followed by an H1, or H2 */
 		& + h1,
diff --git a/src/wp-content/themes/twentynineteen/style-editor.css b/src/wp-content/themes/twentynineteen/style-editor.css
index cd3ad211bb680..76af8b3baaa49 100644
--- a/src/wp-content/themes/twentynineteen/style-editor.css
+++ b/src/wp-content/themes/twentynineteen/style-editor.css
@@ -1293,6 +1293,10 @@ figcaption,
   margin-left: 0;
 }
 
+.wp-block-separator.alignfull:not(.is-style-dots) {
+  width: 100%;
+}
+
 .wp-block-separator.is-style-dots {
   color: #767676;
 }
diff --git a/src/wp-content/themes/twentynineteen/style-editor.scss b/src/wp-content/themes/twentynineteen/style-editor.scss
index ddabf7d6f449e..e52a946415d7c 100644
--- a/src/wp-content/themes/twentynineteen/style-editor.scss
+++ b/src/wp-content/themes/twentynineteen/style-editor.scss
@@ -696,6 +696,10 @@ figcaption,
 		margin-left: 0;
 	}
 
+	&.alignfull:not(.is-style-dots) {
+		width: 100%;
+	}
+
 	&.is-style-dots {
 		color: $color__text-light;
 	}
diff --git a/src/wp-content/themes/twentynineteen/style.css b/src/wp-content/themes/twentynineteen/style.css
index 560d7923297fe..b5f4e6b662828 100644
--- a/src/wp-content/themes/twentynineteen/style.css
+++ b/src/wp-content/themes/twentynineteen/style.css
@@ -6136,6 +6136,11 @@ body.page .main-navigation {
   padding-left: 0.88889em;
 }
 
+.entry .entry-content .wp-block-separator.alignfull:not(.is-style-dots),
+.entry .entry-content hr.alignfull:not(.is-style-dots) {
+  max-width: none;
+}
+
 .entry .entry-content .wp-block-separator + h1:before,
 .entry .entry-content .wp-block-separator + h2:before,
 .entry .entry-content hr + h1:before,