INEOS Britannia is a British sailing team backed by INEOS founder Sir Jim Ratcliffe. The team was initially formed in 2014 and later joined forces with INEOS in 2018. INEOS Britannia was the Challenger of Record for the 37th America's Cup. In this role, they were responsible for organizing the selection series to determine who would compete against the defending champion, Emirates Team New Zealand. However, INEOS Britannia withdrew its challenge for the 38th America's Cup after unsuccessful negotiations with Athena Racing in April 2025.
Sir Ben Ainslie, a four-time Olympic gold medalist, previously served as Team Principal and Skipper. In January 2025, Dave Endean replaced Ainslie as CEO. The team brought together expertise from Formula 1, collaborating with Mercedes-AMG Petronas F1 Team. INEOS Britannia's boats were named "Britannia" in homage to King Edward VII's racing cutter. The team's operational building was located in Portsmouth and included design, manufacturing, administration, and crew development facilities.