diff --git a/web/navigation-sidebar/navigation-sidebar-tab-indicator.css b/web/navigation-sidebar/navigation-sidebar-tab-indicator.css
new file mode 100644
--- /dev/null
+++ b/web/navigation-sidebar/navigation-sidebar-tab-indicator.css
@@ -0,0 +1,12 @@
+.container {
+  width: 4px;
+  height: 32px;
+  border-radius: 0px 4px 4px 0px;
+  position: absolute;
+  left: 0;
+  margin-top: -4px;
+}
+
+.activeContainer {
+  background-color: var(--tab-indicator-primary-active);
+}
diff --git a/web/navigation-sidebar/navigation-sidebar-tab-indicator.react.js b/web/navigation-sidebar/navigation-sidebar-tab-indicator.react.js
new file mode 100644
--- /dev/null
+++ b/web/navigation-sidebar/navigation-sidebar-tab-indicator.react.js
@@ -0,0 +1,22 @@
+// @flow
+
+import classNames from 'classnames';
+import * as React from 'react';
+
+import css from './navigation-sidebar-tab-indicator.css';
+
+type Props = {
+  +isActive: boolean,
+};
+
+function NavigationSidebarTabIndicator(props: Props): React.Node {
+  const { isActive } = props;
+
+  const containerClassName = classNames(css.container, {
+    [css.activeContainer]: isActive,
+  });
+
+  return <div className={containerClassName} />;
+}
+
+export default NavigationSidebarTabIndicator;