Pedro Abad Santos y Basco (Spanish: [ˈpeðɾo aˈβað ˈsantos], Tagalog: [pedro ʔaˈbad ˈsantos]; 31 January 1876 – 15 January 1945) was a Filipino Marxist politician. He founded the Partido Sosyalista ng Pilipinas (PSP) or Philippine Socialist Party in 1929. He ran for several local elections but never won. Luis Taruc of the Hukbalahap Rebellion was under his tutelage and was his right-hand man.