Though not particularly heralded for its night life, these two towns have many places which keep their doors open in to the night, especially in the summer months.
A few of the popular places include:

Y Club - 14 bis rue Désiré Le Hoc, Deauville.

Brok Cafe - 14 avenue du Général de Gaulle, Deauville.

Up And Down Cafe - 90 rue Eugène Colas, Deauville.

Tribune Bar - 1 place Fernand Moreaux, Trouville.