The Grand Oshkosh is a historic opera house located at the corner of High Avenue and Market Street in Oshkosh, Wisconsin. It was built in 1883, and has since undergone two renovations. The first renovation took place during the 1980s and the second in 2009. The theater was listed on the National Register of Historic Places in 1974. The Grand Oshkosh is owned by the City of Oshkosh and leased to and operated by the non-profit Oshkosh Opera House Foundation.