Rosnoën (French pronunciation: [ʁɔsnɔɛn]; Breton: Rosloc'hen) is a commune in the Finistère department of Brittany in north-western France.

Inhabitants of Rosnoën are called in French Rosnoënais.

Rosnoën is located 26 km (16 mi) southeast of Brest.

Térénez bridge is located between Rosnoën and Landévennec.

The bridge crosses the mouth of the Aulne river, connecting Crozon Peninsula to Brittany.