Lac d'Ilay

Lac d'Ilay Lac de la Motte
Location	Jura department, Franche-Comté
Coordinates	46°37′34″N 5°53′51″E
Basin countries	France
Max. length	1.9 km (1.2 mi)
Max. width	0.4 km (0.25 mi)
Surface area	72 ha (180 acres)
Average depth	10.3 m (34 ft)
Max. depth	32 m (105 ft)
Surface elevation	774 m (2,539 ft)
Islands	1 (Île de la Motte)

Lac d'Ilay (or Lac de la Motte) is a lake in the Jura department of France. It has a surface area of 0.72 km².

It is located in the municipalities of Franois and La Chaux-du-Dombief.