51st Field Artillery Regiment is a reserve unit of Philippine Commonwealth Army activated and organized in 1941 and fought during World War II.

The regiment is a component of 51st Infantry Division under Brigadier General Albert M. Jones, responsible for the defense of Bicol Peninsula.

[3] The regiment first saw action when Japanese moved inland after their landings in San Miguel Bay, in Legazpi, Albay.

It provided fire support for 52nd Infantry Regiment under Lieutenant Colonel Virgilio Cordero fighting a delaying action in Camarines Sur and Norte provinces.

It was posted in II Corps Area under the former South Luzon Force commander Major General George M. Parker.