The Grand Opera House is an historic opera house located at the corner of High Avenue and Market Street in Oshkosh, Wisconsin, United States. It was built in 1883, and underwent a major refurbishing in 2009–2010 at an expense of two million dollars. The roof trusses were reinforced, the ceilings were replaced, and a large chandelier was repaired. Additionally a new "Grand Lounge" was added for improved audience services and to smaller events. Today, the opera house seats 600, hosts nearly 100 public performances a year including community and repertory theater, symphony orchestra, corporate meetings and weddings; it is operated by the non-profit Oshkosh Opera House foundation. The theater was listed on the National Register of Historic Places in 1974.