diff --git src/wp-admin/css/themes.css src/wp-admin/css/themes.css
index 89fafd5..8c954e5 100644
--- src/wp-admin/css/themes.css
+++ src/wp-admin/css/themes.css
@@ -828,6 +828,13 @@ body.folded .theme-overlay .theme-wrap {
 }
 
 /**
+ * Theme deletion dialog
+ */
+#delete-theme-dialog #delete-theme-dialog-message {
+	padding: 15px 25px;
+}
+
+/**
  * Basic Responsive structure...
  *
  * Shuffles theme columns around based on screen width
diff --git src/wp-admin/js/theme.js src/wp-admin/js/theme.js
index 1a91279..795fc1c 100644
--- src/wp-admin/js/theme.js
+++ src/wp-admin/js/theme.js
@@ -714,9 +714,47 @@ themes.view.Details = wp.Backbone.View.extend({
 		this.trigger( 'theme:collapse' );
 	},
 
-	// Confirmation dialog for deleting a theme
-	deleteTheme: function() {
-		return confirm( themes.data.settings.confirmDelete );
+	// Called by Themes view
+	keyEvent: function(e) {
+		// Pressing the right arrow key fires a theme:next event
+		if ( e.keyCode === 39 ) {
+			self.overlay.nextTheme();
+		}
+
+		// Pressing the left arrow key fires a theme:previous event
+		if ( e.keyCode === 37 ) {
+			self.overlay.previousTheme();
+		}
+
+		if ( e.keyCode === 27 ) {
+			if ( $( '#delete-theme-dialog' ).hasClass( 'hidden' ) ) {
+				// Pressing the escape key fires a theme:collapse event
+				self.overlay.collapse( event );
+			} else {
+				// Close theme deletion dialog
+				$( '#delete-theme-dialog' ).addClass( 'hidden' );
+			}
+		}
+
+		if ( e.keyCode === 9 && !$( '#delete-theme-dialog' ).hasClass( 'hidden' ) ) {
+			// Constrain tabbing within the theme deletion dialog
+			var $target = $( e.target );
+		}
+	},
+
+	// Confirmation dialog for deleting a theme.
+	deleteTheme: function(e) {
+		e.preventDefault();
+
+		var originalTarget = $( e.target );
+
+		$( '#delete-theme-dialog' ).removeClass( 'hidden' ).focus();
+
+		$( '#delete-theme-dialog-cancel' ).on( 'click', function () {
+			$( '#delete-theme-dialog' ).addClass( 'hidden' );
+		} );
+
+		$( '#delete-theme-dialog-confirm' ).attr( 'href', $( '.delete-theme' ).attr( 'href' ) );
 	},
 
 	nextTheme: function() {
@@ -901,20 +939,7 @@ themes.view.Themes = wp.Backbone.View.extend({
 				return;
 			}
 
-			// Pressing the right arrow key fires a theme:next event
-			if ( event.keyCode === 39 ) {
-				self.overlay.nextTheme();
-			}
-
-			// Pressing the left arrow key fires a theme:previous event
-			if ( event.keyCode === 37 ) {
-				self.overlay.previousTheme();
-			}
-
-			// Pressing the escape key fires a theme:collapse event
-			if ( event.keyCode === 27 ) {
-				self.overlay.collapse( event );
-			}
+			self.overlay.keyEvent( event );
 		});
 	},
 
diff --git src/wp-admin/themes.php src/wp-admin/themes.php
index bf65884..afb6d61 100644
--- src/wp-admin/themes.php
+++ src/wp-admin/themes.php
@@ -129,10 +129,9 @@ wp_reset_vars( array( 'theme', 'search' ) );
 wp_localize_script( 'theme', '_wpThemeSettings', array(
 	'themes'   => $themes,
 	'settings' => array(
-		'canInstall'    => ( ! is_multisite() && current_user_can( 'install_themes' ) ),
-		'installURI'    => ( ! is_multisite() && current_user_can( 'install_themes' ) ) ? admin_url( 'theme-install.php' ) : null,
-		'confirmDelete' => __( "Are you sure you want to delete this theme?\n\nClick 'Cancel' to go back, 'OK' to confirm the delete." ),
-		'adminUrl'      => parse_url( admin_url(), PHP_URL_PATH ),
+		'canInstall' => ( ! is_multisite() && current_user_can( 'install_themes' ) ),
+		'installURI' => ( ! is_multisite() && current_user_can( 'install_themes' ) ) ? admin_url( 'theme-install.php' ) : null,
+		'adminUrl'   => parse_url( admin_url(), PHP_URL_PATH ),
 	),
  	'l10n' => array(
  		'addNew'            => __( 'Add New Theme' ),
@@ -456,10 +455,21 @@ $can_install = current_user_can( 'install_themes' );
 			</div>
 
 			<# if ( ! data.active && data.actions['delete'] ) { #>
-				<a href="{{{ data.actions['delete'] }}}" class="button button-secondary delete-theme"><?php _e( 'Delete' ); ?></a>
+				<a href="{{{ data.actions['delete'] }}}" class="button button-secondary delete-theme" aria-label="<?php esc_attr_e( 'Confirm deletion' ); ?>"><?php _e( 'Delete' ); ?></a>
 			<# } #>
 		</div>
 	</div>
 </script>
-
+<div id="delete-theme-dialog" class="notification-dialog-wrap hidden" role="dialog" aria-label="<?php esc_attr_e( 'Confirm deletion' ); ?>" tabindex="0">
+	<div class="notification-dialog-background"></div>
+	<div class="notification-dialog">
+		<div id="delete-theme-dialog-message">
+			<p><?php _e( 'Are you sure you want to delete this theme?' ); ?></p>
+			<p>
+				<button id="delete-theme-dialog-confirm" class="button button-primary"><?php _e( 'Delete' ); ?></button>
+				<button id="delete-theme-dialog-cancel" class="button button-secondary"><?php _e( 'Cancel' ); ?></button>
+			</p>
+		</div>
+	</div>
+</div>
 <?php require( ABSPATH . 'wp-admin/admin-footer.php' );