HMS Severn is a River-class offshore patrol vessel of the Royal Navy. Named after the River Severn, the ship is the first to bear the name in 56 years. She was built by Vosper Thornycroft in Southampton to serve primarily as a fishery protection unit within the United Kingdom's waters along with her two sister ships Mersey and Tyne. All three were commissioned into service in 2003 to replace the five older Island-class patrol vessels. The ship was decommissioned in 2017, but the Government decided to recommission her as part of Brexit preparedness, and the ship was therefore refitted in 2020.