Wightlight received the title during the 2017 Loo of the Year Awards.
The ferry firm’s on board facilities on the Portsmouth-Fishbourne ships St Faith and St Clare received platinum awards after an independent inspection of the washrooms
The company also received a national award.
Wightlink operations director Daryl Palmer said: ‘I am proud of our colleagues who do their best every day to keep all of the toilets on board our eight ferries and catamarans as clean and tidy as possible.’
Running since 1987, the awards have been highlighting the top washrooms in Britain, with titles graded from bronze to platinum.
Entries receive an unannounced visit from an inspector and is assessed against 101 criteria including signage, décor, fixtures and cleanliness.