By 1964 when it was dissolved, Ytterøy only included the 28 square kilometres (11 sq mi) island of Ytterøya.

[8] The municipality (originally the parish) is named after the island of Ytterøya (Old Norse: Øyin ýtri, or more recently Ýtriøy) since the first Ytterøy Church was built there.

The first element of the original name is the definite singular form of øy which means "island".

At the time of the municipal dissolution, it was part of the Ytterøy prestegjeld and the Sør-Innherad prosti (deanery) in the Diocese of Nidaros.

[7] The highest point in the municipality was the 210-metre (690 ft) tall mountain Sandstadheia on the western end of the island of Ytterøya.

The municipal council (Herredsstyre) of Ytterøy was made up of 13 representatives that were elected to four year terms.