The 4th constituency of Morbihan is a French legislative constituency in the Morbihan département.

Like the other 576 French constituencies, it elects one MP using the two-round system, with a run-off if no candidate receives over 50% of the vote in the first round.

The constituency covers the eastern areas of Morbihan.

At the 2017 election Paul Molac of En Marche!

[1] * Withdrew before the 2nd round * PS dissident