From 1837, Eiksund was administratively a part of Herøy, despite being separated from the rest of Herøy by the sea. On 1 January 1964 it was therefore moved to Ulstein together with the island Eika, which is located just south of Eiksund. At that time Eika and EIksund had 222 inhabitants combined.
Until 2008, Eiksund was connected to Rjåneset in Ørsta by ferry. On 23 February 2008, an undersea tunnel, Eiksund tunnel, is was opened by the Norwegian Minister of Transport and Communications, Liv Signe Navarsete.
The Eiksund Tunnel is the world's deepest road tunnel, with its lowest point at 287 meters below sea level.