Lakeside School is a private school (grades 5 through 12) located in the Haller Lake neighborhood at the north city limits of Seattle, Washington. It was founded in 1919 as the Lakeside Day School for Younger Boys in Denny-Blaine, moved to the present site of the Bush School in 1923, and a few years later moved to its present location. It became coeducational upon merger with St. Nicholas, a Capitol Hill girls' school, in 1971.

Its most famous alumni are likely Bill Gates and Paul Allen, founders of Microsoft.

Facts and figures (as of September 2002):
Enrollment: 724 (370 boys, 354 girls)
Faculty: 89
Tuition: Grades 5-8: $16,825; Grades 9-12: $17,525

Official site