Patrick J. Hannifin (born January 26, 1923) is a retired American Navy vice admiral. Hannifin was born in 1923 in Oklahoma to Steven Patrick and Elizabeth (née Flanagan) Hannifin. He attended the New Mexico Military Institute prior to going to the United States Naval Academy, in which he graduated in 1944. Hannifin served in World War II on the submarine USS Balao (SS-285), and after the war he eventually held commands of the USS Diodon (SS-349), USS George Washington (SSBN-598), USS Lafayette (SSBN-616) as well as Submarine Squadron 15, in 1968, which he was given responsibility for all the Polaris submarines in the Pacific Fleet in Guam.