Niagara District Court House, Courthouse in Niagara-on-the-Lake, Canada.

Niagara District Court House is a three-storey neo-classical building of 1846–1847, designed by Toronto architect William Thomas and built by Garvie and Co. Inside were a courtroom, town hall chambers, offices and jail cells. It is now the Shaw Festival's Court House Theatre, used since 2018 for rehearsals, training and education rather than performances.

The 1847 courthouse, designed by Toronto architect William Thomas and built by Garvie and Co., replaced an 1817 Georgian courthouse near Rye and Cottage Streets that stood beyond cannon range from Fort Niagara. The first courthouse, a 1795 blockhouse at King and Prideaux Streets, was burned by American troops in 1813. The building served as a courthouse until 1863, when the courts moved to St. Catharines.

The building's name shifted with its uses: court house, town hall and jail, then a girls' orphanage from England from 1869, and from 1962 the Court House Theatre of the Shaw Festival. It was retired as a performance venue after the 2018 season and now serves rehearsals, training and education.

The building stands at 26 Queen Street in Niagara-on-the-Lake, a short walk from Queen Street's shops and restaurants. Since the 2018 season it no longer hosts main-stage performances; it is used for rehearsals, training and education, so access depends on the Shaw Festival's programme. The three-storey interior is reached by staircases.

The building hosted the 1850 Provincial Agricultural Fair of Canada West, one of its early non-judicial uses. From 1869 to the early 20th century it served as an orphanage for girls from England. It was designated a National Historic Site in 1981.