The Battle of Arica, also known as Assault and Capture of Cape Arica, was a battle in the War of the Pacific. It was fought on 7 June 1880, between the forces of Chile and Peru.

After the Battle of Tacna and the following Bolivian withdrawal from the war, Peru had to stand alone for the rest of the conflict. The need for a port near to the location of the army, in order to supply and reinforce the troops and evacuate wounded, made the Chilean command put its attention on the remaining Peruvian stronghold in the Tacna Department. The Chilean army, led by Colonel Pedro Lagos, launched a giant assault to Arica, where the 1600 men of the defense fought more than 8000 Chileans, from sea and land, who finally captured the Morro de Arica (English: Cape Arica) after 55 minutes of combat. The defending Peruvian troops under the command of Colonel Francisco Bolognesi died as heroes. In this fight the old Peruvian Commander died along with several officers and more than 1,000 men.The Chilean victory ended the phase of the conflict known as Campaa de Tacna y Arica (English: Campaign of Tacna and Arica), resulting in the occupation of the entire Tarapac and Tacna provinces. After this action, a new stage began named Campaa de Lima (English: Lima Campaign), which concluded with the fall of the Peruvian capital city seven months later.

The city of Arica never returned to Peruvian hands. It was temporarily ceded to Chile after the signing of the Treaty of Ancon, on 1884; the city remained occupied by Chilean forces until the later signing of the Treaty of Lima in 1929, when it was ceded permanently to Chilean sovereignty.

The War of the Pacific (Spanish: Guerra del Pacífico), also known as the Saltpeter War (Spanish: Guerra del salitre) and by multiple other names, was a war between Chile and a Bolivian–Peruvian alliance from 1879 to 1884. Fought over Chilean claims on coastal Bolivian territory in the Atacama Desert, the war ended with a Chilean victory, which gained for the country a significant amount of resource-rich territory from Peru and Bolivia.

The war began over a nitrate taxation dispute between Bolivia and Chile, with Peru being drawn in due to its secret alliance with Bolivia. But historians have pointed to deeper origins of the war, such as the interest of Chile and Peru in the nitrate business, the long-standing rivalry between Chile and Peru, as well as political and economical disparities between Chile and Peru and Bolivia. On February 14, 1879, Chile's armed forces occupied the Bolivian port city of Antofagasta, subsequently war between Bolivia and Chile was declared on March 1, 1879, and between Chile and Peru on April 5, 1879.

Battles were fought in the Pacific Ocean, the Atacama Desert, the Peruvian deserts, and the mountainous interior of Peru. For the first five months, the war played out in a naval campaign, as Chile struggled to establish a marine resupply corridor for its forces in the world's driest desert. Afterwards, Chile's land campaign bested the Bolivian and Peruvian armies. Bolivia withdrew after the Battle of Tacna, on May 26, 1880. Chilean forces occupied Peru's capital Lima in January 1881. Remnants and irregulars of the Peruvian army waged a guerrilla war but could not prevent war-weary Peruvian factions from reaching a peace deal with Chile involving territorial cessions.

Chile and Peru signed the Treaty of Ancón on October 20, 1883. Bolivia signed a truce with Chile in 1884. Chile acquired the Peruvian territory of Tarapacá, the disputed Bolivian department of Litoral (turning Bolivia into a landlocked country), and the temporary control over the Peruvian provinces of Tacna and Arica. In 1904, Chile and Bolivia signed the Treaty of Peace and Friendship, which established definite boundaries. The 1929 Tacna–Arica compromise gave Arica to Chile and Tacna to Peru.