Lannilis (French pronunciation: [lanilis]; Breton: Lanniliz) is a commune in the Finistère department of Brittany in north-western France.

Inhabitants of Lannilis are called in French Lannilisiens.

The municipality launched a linguistic plan concerning the Breton language through Ya d'ar brezhoneg on 27 June 2008.

In 2008, 33.17% of primary-school children attended bilingual schools.

[5] A population of Cacous, a persecuted minority of ropemakers, still lived isolated in the village of Trebirou [Trobérou] in Lannilis in 1847.