The 18 May 1811 Medal (Spanish: Medalla 18 de Mayo 1811) is the second highest military decoration of the Uruguayan Army. The medal was established 16 December 1997 to complement the Medal of Military Merit, the highest decoration of the Uruguayan Army, and commemorates the Battle of Las Piedras which took place on that date. The medal is presented in three classes and are awarded based on the rank of the recipient. The medal is awarded to Uruguayan and foreign military officers, as well as civilians, for outstanding achievement and meritorious service.