The Freie Schule Winterthur is a non-profit private school at Heiligbergstrasse in Winterthur, founded in 1873. It teaches Grade 6, a transition year, and the secondary levels Sek A and Sek Plus, with a route from a third year of Sek B into the third year of Sek A. The school prepares students for apprenticeships, for the Mittelschule and for the long-form gymnasium. Its first-year Sek A and Sek Plus classes for 2026/27 are full, with a few places remaining in the transition year and Grade 6.