In 1954 he was elected the 16th Governor of New Mexico at the age of 38, at the time the youngest governor to be elected in New Mexico. Governor Simms died on April 11, 1975. Governor Simms was a Democrat.
The John F. Simms building in Santa Fe is named after the late governor.
He was a member of the New Mexico House of Representatives from 1947 to 1949.