Gilbert Franklin Hennigan (December 18, 1883 – November 4, 1960) was a three-term Democratic member of the Louisiana State Senate, who served from 1944 to 1956 under Governors Jimmie Davis, Earl Kemp Long, and Robert F. Kennon.
Hennigan was born in rural Meadows in Calcasieu Parish near Lake Charles in southwestern Louisiana.
Hennigan and his wife, the former Myrtie Mae Whitman (1888-1927), whom he married at Brushy Creek in Beauregard Parish in 1906, had eight children.
That same year, he was elected to succeed Ernest S. Clements to the first of three terms in the state Senate from Allen, Beauregard, Calcasieu, Cameron, and Jeff Davis parishes.
In 1950, he was instrumental in the creation of McNeese State University as a four-year college in Lake Charles.