Watson Island is a neighborhood and man-made island in Biscayne Bay in Miami, Florida, United States. Immediately east of the Omni neighborhood of downtown Miami, it is connected to the mainland and South Beach, Miami by the MacArthur Causeway.
The island was created by land reclamation in 1926 with material dredged from the ship channel to the Port of Miami, and was originally named Causeway Island. The island was later named for John W. Watson, Sr., who was Mayor of Miami 1912-1915 and 1917-1919.
It is the site of the annual Swim Miami open water swim event presented by Nike in April.