Tysnesøya (Urban East Norwegian: [ˈtŷːsneːsˌœʏɑ]) or Tysnesøy is an island in Tysnes municipality in Vestland county, Norway.

The tallest point on the island is the 753-metre (2,470 ft) tall mountain Tysnessåto.

The islands of Skorpo and Reksteren are connected to Tysnesøya by road bridges.

The mainland lies just east of Tysnesøya, and there is a short road bridge connecting the two.

The main agricultural areas are in the northeast and south.