Pheasant Island (German: Fasaneninsel) is one of the two islands in the south of the lake of Großer Eutiner See, which itself lies in the borough of Eutin in the district of Ostholstein in the German state of Schleswig-Holstein.

From the 9th century, Pheasant Island was the site of a Wendish castle which was given the name Utin and was the centre of the eponymous Gau.

The subsequent settlement was built on the shore and developed into the present-day town of Eutin.

Pheasant Island is one of the landmarks of the visual axes of the former Baroque garden of Eutin Castle.

Today, the island is privately owned and inhabited.