Mariano Arista (26 July 1802 – 7 August 1855) was a noted veteran of many of Mexico's nineteenth century wars who served as president of Mexico from January 15, 1851 to January 6, 1853.

He was born in the state of San Luis Potosí. Originally an officer in the Spanish Army, Arista later joined the revolutionary army of Agustín de Iturbide. Later, he served under Antonio López de Santa Anna, Mexico's on-again off-again dictator during the attempt to put down the 1836 Texas Revolution.

In 1846, Arista was given command of the Army of the North and sent to expel American troops from Mexican territory in Texas. The resulting engagement ignited the bloody Mexican-American War of 1846 - 1848. Arista was in command of Mexican forces during the Battle of Palo Alto and the Battle of Resaca de la Palma.

While personally quite brave, Arista was a dedicated republican - a member of Mexico's liberal faction, and therefore the natural enemy of his largely conservative general staff. At both the Battles of Palo Alto and Resaca de la Palma, Arista was ill served by the political division among his staff.

After Resaca de la Palma, Mexico's government recalled Arista and he was removed from command. Later absolved of guilt for the defeats at Palo Alto and Resaca de la Palma, Arista spent the rest of the war as a functionary, seeing little combat.

In 1851, Arista succeeded José Joaquín de Herrera as president, and sought to bring fiscal stability to the nation. Conservative resistance to Arista's rule, and an eventual revolt by the said conservatives led to his resignation and exile in 1853.

He died on board the English steamer Tagus going from Lisbon, Portugal, to France on 7 August 1855. In 1880 his remains were returned to Mexico, where the Liberal faction named him a national hero.