The Hay Gaol is of State significance for its variety of historical functions as a prison and detention centre. It was built as a colonial prison in 1880 but more significantly was used as a detention and hospitalisation facility servicing Hay's World War II internment and prisoner of war camps (1940 - 1946) and then as a girls' institution run by the NSW Department of Child Welfare (1961 - 1974). The Hay Gaol is of local historical significance as one of several grand buildings that represent Hay's unfulfilled promise of becoming the capital of the Riverina, and for its temporary roles as a maternity hospital (1920 to 1930) and as a site of emergency accommodation during the 1952 and 1956 floods. For its museum collections relating to the social and pastoral history of Hay, the gaol also has local significance.