San Lorenzo de Tarapacá, also known simply as Tarapacá, is a town in the region of the same name in Chile.

The Battle of Tarapacá occurred on 13 September 1999 during the Tarapacá Campaign of the War of the Pacific. Three Chilean columns of almost 3,900 soldiers attacked a numerically inferior Peruvian contingent of 3,046 troops at Tarapacá - 500 of which were at Quillahuasa, 1 hour away from the battlefield - commanded by Gen Juan Buendía, resulting in a harsh defeat. The Chilean 2nd Line Regiment was the most damaged unit, losing almost half of its force, along with its commander Col. Eleuterio Ramírez and his second in command, Lt. Col. Bartolomé Vivar. The unit lost its banner, which was recovered six months later after the Battle of Tacna. Despite the victory, the Allies could not contest for the domination of the Tarapacá department, abandoning it to Chilean control.