St John the Baptist Church is a parish church in Windsor in the English county of Berkshire. It is dedicated to St John the Baptist. The church was rebuilt in Gothic Revival style in 1822. It is the civic church of Windsor, and many Mayors of Windsor are buried in the church and churchyard. The church is Grade II* listed. Two of the three Protestant Windsor Martyrs, who were burnt at the stake in 1543, were associated with the church.