Tyssøyna or Tyssøy is an island in Øygarden Municipality in Vestland county, Norway.

On the western side of the island is a wide and sheltered harbour called Tyssøyvågen.

Further inland on Tyssøy is a larger soapstone locality, bearing traces of being quarried for building material, most probably of a Medieval date.

This indicates that the earliest possible date for the figure at the inlet of Tyssøyvågen is the Middle Ages.

1305), the Norwegian king Haakon V built a royal chapel on the island.