Pelagio Baltasar Luna (6 January 1867 – June 25, 1919) was an Argentine politician of the Radical Civic Union. He was elected Vice President in 1916. Born in La Rioja, Argentina, where his father was founder of the Radical Civic Union, Luna graduated from the University of Buenos Aires at the age of 22. He returned to La Rioja and worked as a lawyer then entered the judicial system, serving as a judge. He also taught literature at the National School of La Rioja.