Located north of, and connected by a bridge to, Key Vaca at MM???.

Both Gauld (1775), and Blunt (1846) charts show Stirup's Kay. A Spanish Derrotero, or sailing directions written in 1820 shows Cayos de Estribo. Estribo is the Spanish word for stirrup.

There exists documentation that In 1763, a Bahamian sea captain named Stirrup visited the Florida Keys, and it seems likely that this key may have been named for him, as few of the bayside keys were named so early as this one.