Vice Admiral Francisco Nef Jara (August 3, 1863 – June 9, 1931) was a Chilean naval officer and member of the Government Junta that ruled Chile between 1924 and 1925. Nef was born in Valparaiso. At the age of 16, on March 1, 1879, he joined the Military Academy, where he remained until 1881, when he transferred to the Naval Academy to finish his studies. By 1883, he already was a second-class ensign and joined the crew of the ironclad Blanco, under the command of future president Jorge Montt. During the remainder of the War of the Pacific, he served in the O'Higgins, Chacabuco (blockading Pacocha, in northern Peru), Abtao (patrolling the extreme south of Chile), Cochrane and Pilcomayo.