Guillermo Arbulú Galliani (March 1, 1921 – 1998) was a Peruvian general and politician. He was born in Trujillo, Peru. He served as Ambassador of Peru to Spain and Chile. He studied at the Chorrillos Military School and the Center for Higher National Studies in Lima. He went briefly to the United States for further studies at Fort Belvoir, Virginia. He was promoted to brigadier general in 1971 and major general in 1975. He was Prime Minister of Peru (July 1976 – January 1978). He was simultaneously minister of war in the Government of Peru.