Southsea Castle courtyard can be accessed via a bridge over the moat. This is on one level but cobbled almost throughout, so visitors are advised to take care.
Access to the keep and ramparts is only available via stairs, so are not suitable for those with mobility impairments. However, The Courtyard, shop and microbrewery are all at ground level.
Disabled parking is available at the nearby D-Day Story car park, which is a short and flat walk from the castle.
Guide dogs, hearing dogs and assistance dogs wearing appropriate tabards are permitted in the keep. Non-assistance dogs are not allowed in the keep but are permitted in the courtyard – where water bowls are provided.