Abstract: A foldable peep sight according to the teachings of the present invention is shown for use with a firearm such as a rifle. A peep sighting member is mounted on an arm. The arm is pivotally mounted about a horizontal axis which is generally parallel to but spaced from the gun barrel by an arcuately shaped mount. The arm is pivotal between a first, non-sighting, transport, storage position adjacent the gun barrel and a second, sighting position spaced from the gun barrel and in firing alignment with the front sight of the firearm to allow aiming of the firearm by aligning the firearm to have the peep sight and the front sight of the firearm in line with the target. A spring located between a spring block attached to the mount and a leg attached to the arm biases the arm to its second, sighting position.