Lilian Mercedes Letona (September 24, 1954 – August 1, 1983), was a Salvadoran guerrilla and communist revolutionary, member of the Farabundo Martí National Liberation Front (FMLN).

Born in 1954 in Turín, a town located in the Ahuachapán Department, she was the daughter of a school teacher and a small tradeswoman.

Graduated in 1972 in painting, she was member of a student movement before to join the Ejército Revolucionario del Pueblo (ERP - People's Revolutionary Army),[2][3] while promoting the incorporation of her sister Mercedes del Carmen Letona (nom de guerre Comandante Luisa) who later became a responsible of Radio Venceremos.

In January 1974, aged 19, she went underground to avoid persecutions and joined the armed struggle, where she partecipe to the construction of the Partido de la Revolución Salvadoreña (PRS-ERP - Salvadoran Revolution Party,[5] one of the founding subjects of the FMLN)[6] becoming a member of its central committee in 1977.

As member of it, she was responsible for the party and participated in the preparation of the general offensive of 1981 around the city of San Salvador, when she was captured of February 11.