La Bluette, Art Nouveau cottage in Hermanville-sur-Mer, France.

La Bluette is a two-storey Art Nouveau villa at 272 rue du Pré-de-l'Isle in Hermanville-sur-Mer, built in 1899 by Hector Guimard. Its limestone and pebble walls are divided by blue-painted timber framing, and the steep tiled roof carries a tall stone chimney on the left slope and a smaller stack on the right. A projecting upper balcony with a blue railing and white panels, two blue-framed windows and a blue picket fence with stone pillars face the street.

Hector Guimard designed La Bluette in 1899 for Prosper Grivellé, a Parisian lawyer, as one of the seaside villas built between Lion-sur-Mer and Hermanville-sur-Mer. It is one of only two surviving houses from Guimard's first building period. Around 1925 a garage with a room above was added. The house was partly listed as a monument historique by decree of 15 December 2005.

La Bluette belongs to the wave of seaside villas built from Lion-sur-Mer to Hermanville-sur-Mer, and is also known as la Houle. Its blue-painted woodwork is the most visible mark of Guimard's Art Nouveau on the Calvados coast, where the style is rare.

La Bluette stands at 272 rue du Pré-de-l'Isle, on the digue de la Brèche in Hermanville-sur-Mer. It is a private residence, so visitors view it from the street; the blue-painted timber frame, balcony and front fence are seen from the pavement. The ground-floor plan Guimard drew is held at the Musée d'Orsay, not on site.

A ground-floor plan drawn by Guimard for La Bluette is held at the Musée d'Orsay in Paris. The house is also known as la Houle, and its roof is crowned by a ceramic wave. Of Guimard's first building period, only this house and one other survive.