No biographical details are currently known.
He has a small speaking role in El extraño amor de los vampiros, which has fairly extensive credits, so I investigated further. García López has 4 credits listed on IMDb (discounting one mis-credit - see "No Francisco" below), in 2 of which we already had him identified and he has a small speaking role in the other. Since 3 of his 4 credited roles are small speaking parts that might be credited, then I think the identification is as certain as it can be.
He has a similar look to unidentified Italian generico "Lurch" - tall, thin, bald, with a moustache - hence his previous nickname, Largo being the Spanish name for the Lurch character in The Addams Family.
- Amor sobre ruedas .... Reporter (uncredited)
- Morena Clara .... Party guest (uncredited)
1955 - Al fin solos .... Nightclub customer (uncredited)
- El indiano .... Man in Jolanda's dressing room (uncredited)
- Historias de la radio .... Radio station office worker (uncredited)
- La lupa .... Nightclub customer (uncredited)
- Suspiros de Triana .... Ship passenger (uncredited)
1956 - El expreso de Andalucía .... Man queueing in the post office / Man in funeral procession (uncredited)
- Esa voz es una mina .... Singing contest audience member (uncredited)
- La vida en un bloc .... Nightclub customer (uncredited)
- Suspenso en comunismo .... Student in communism class (uncredited)
- Tarde de toros .... Man in the hotel lobby / Bullfight spectator (uncredited)
- Todos somos necesarios .... Train passenger (uncredited)
1957 - La Cenicienta y Ernesto .... Guest at the ball (uncredited)
- Las muchachas de azul .... Man leaving subway (uncredited)
- Totò, Vittorio e la dottoressa .... Nightclub customer (uncredited)
- Un angelo è sceso a Brooklyn .... Passerby (uncredited)
- Un marido de ida y vuelta .... Board member (uncredited)
1958 - Aquellos tiempos del cuplé .... Hotel guest / Boxing spectator (uncredited)
- El Cristo de los Faroles .... Theatre audience member (uncredited)
- El fotogénico .... Dance contest spectator (uncredited)
- El hincha .... Football spectator / Nightclub customer (uncredited)
- El tigre de Chamberí .... Reporter (uncredited)
- Historias de Madrid .... Fireman (uncredited)
- La violetera .... Nightclub customer (uncredited)
- Las chicas de la Cruz Roja .... Man at the awards ceremony / Press photographer (uncredited)
- Muchachas en vacaciones .... Man at the bus stop (uncredited)
1959 - La vida alrededor .... Judge (uncredited)
- Las dos y media y... veneno .... Man enquiring about funeral services (credited as "Francisco Gª Lopez")
- María de la O .... Nightclub customer (uncredited)
- Marinai, donne e guai .... Nightclub customer (uncredited)
- Parque de Madrid .... Man in concert audience (uncredited)
1960 - Amor bajo cero .... Waiter (uncredited)
- Don Lucio y el hermano Pío .... Disembarking train passenger (uncredited)
- El cerro de los locos .... Stagehand (uncredited)
- El indulto .... Prisoner (uncredited)
- El vagabundo y la estrella .... Police officer (uncredited)
- La quiniela .... Man at the bus stop (uncredited)
- Los económicamente débiles .... Wrestling spectator (uncredited)
- Melodías de hoy .... Waiter (credited as "Francisco Garcia")
- Mi último tango .... Ship passenger (uncredited)
- Un ángel tuvo la culpa .... Police secretary / Neighbour (uncredited)
- Un bruto para Patricia .... Party guest (uncredited)
- Un rayo de luz .... Parent at the concert (uncredited)
- Y el cuerpo sigue aguantando .... Restaurant customer (uncredited)
1961 - A las cinco de la tarde .... Nightclub customer (uncredited)
- Aquí están las vicetiples .... Construction worker (uncredited)
- Los pedigüeños .... Nightclub customer (uncredited)
- Tres de la Cruz Roja .... Passerby (uncredited)
1962 - El balcón de la Luna .... Nightclub customer (uncredited)
- El grano de mostaza .... Man in the gentlemen's club (uncredited)
- Escuela de seductoras .... Filiberta's father (uncredited)
- Il terrore di notte .... Party guest (uncredited)
- Rogelia .... Man at the wake (uncredited)
1963 - El sabor de la venganza .... Saloon customer (uncredited)
1964 - Búsqueme a esa chica .... Man at the airport (uncredited)
- El extraño viaje .... Man questioned by the police (uncredited)
- Fuera de la ley .... Troublemaker (uncredited)
- Vacaciones para Ivette .... Swimming coach (uncredited)
1965 - Amador .... Arriving plane passenger (uncredited)
- Crack in the World .... Reporter (uncredited)
- El arte de vivir .... Man at the art exhibition (uncredited)
- El cálido verano del Sr. Rodríguez .... Pool hall customer / Bar customer (uncredited)
- Historias de la televisión .... Man in family group watching TV / Swimming coach (uncredited)
- La familia y... uno más .... Wedding guest (uncredited)
- Más bonita que ninguna .... Man in cinema audience (uncredited)
1966 - Agente Logan - missione Ypotron .... Man at the airport (uncredited)
- La busca .... Dinner guest (credited)
- La mujer perdida .... Dinner theatre customer (uncredited)
- Las viudas .... Wedding guest (uncredited)
- Per mille dollari al giorno .... Poker player (uncredited)
- Proceso a una estrella .... Bar customer (uncredited)
1968 - Comanche blanco .... Saloon customer (uncredited)
- Los que tocan el piano .... Bar customer (uncredited)
1969 - ¡¡Se armó el belén!! .... Man in church (uncredited)
- Amor a todo gas .... Radio broadcast audience member (uncredited)
- El perfil de Satanás .... Man at the banquet (uncredited)
1970 - Juan y Junior... en un mundo diferente .... Journalist at press conference (uncredited)
1972 - Dos chicas de revista .... Theatre audience member (uncredited)
1973 - Don Quijote cabalga de nuevo .... Man in Sancho Panza's court (uncredited)
1974 - ...altrimenti ci arrabbiamo! .... Man who delivers the dune buggy (uncredited)
- Cuando los niños vienen de Marsella .... Bar customer (uncredited)
- Fantasma en el Oeste .... Casino waiter (uncredited)
- Matrimonio al desnudo .... Board member (uncredited)
- Sex o no sex .... Office worker (uncredited)
1975 - Como matar a papá... sin hacerle daño .... Man at the wake (uncredited)
- El extraño amor de los vampiros... .... Tavern customer (credit unknown)
1976 - Los hijos de... .... Man at the funeral (uncredited)
1977 - El espiritista .... Judge at the tribunal (uncredited)
- El perro .... Prison Commander's Deputy (uncredited)
- La Coquito .... Man wanting a date with La Coquito (uncredited)
- Niñas... al salón .... Film censor (uncredited)
1978 - El diputado .... Secretary (uncredited)
- El sacerdote .... Waiter (uncredited)
- Un hombre llamado Flor de Otoño .... Garcia (uncredited)
- Pistoleros de Arizona (1965) IMDb as "Bit part". The credit here is for "Francisco Garcia", which our man does have one credit as, but this film was shot in Barcelona while Francisco was certainly based in Madrid, and he does not appear, so this must presumably belong to another actor.