Union Day School is the only charter school in the state and in the Charlotte area to offer the International Baccalaureate (IB) to its students beginning in sixth through twelve.

Based in Weddington, NC, Union Day School serves families throughout the greater Charlotte Metroplex, primarily in communities in Union County and the southern portion of Mecklenburg County, such as Charlotte, Weddington, Matthews and Waxhaw. UDS began operating in the 2016-17 school year as a K-3 school, adding one grade annually.

Union Day School now serves students in grades K-12 in the 2025-26 school year and will award high school diplomas to its first graduating class in June 2026.