Lake Washington is a lake in Le Sueur County, Minnesota and Blue Earth County, Minnesota, in the United States. The lake has a regional park, located on the northwest shore, which was acquired in two phases in 1971 and 1978. The park serves as a campgrounds area. The first structure on the lake was built in 1898. The lake has a summer camp for children on the lake, Camp Patterson, which hosts an average of 2,500 kids throughout the summer.
Lake Washington was named for President George Washington.