Old Portsmouth is a district of the city of Portsmouth. It is the area covered by the original town of Portsmouth as planned by Jean de Gisors. It is situated in the south west corner of Portsea Island.
Areas and buildings within Old Portsmouth include: Portsmouth Cathedral, Royal Garrison Church/Domus Dei, The John Pounds Memorial Church (Unitarian), the Square Tower and Round Tower and Point Barracks, Portsmouth Point and the entrance to the Harbour.