UNIFI is a British Trades Union that represents over 160,000 staff employed in banks, building societies, insurance companies and finance houses in the United Kingdom. It was created in 1999 through the merger of the the Banking, Insurance and Finance Union or BIFU, the Union of Royal and Sun Alliance Staff, the Natwest Staff Association, and the former Barclays Group Staff Union which had itself been using the "Unifi" name since 1995.

It is the tenth largest union in the United Kingdom and the largest finance union in the world. It is affiliated to both the Trades Union Congress and Union Network International.