The energy provider is partnering with cinema advertising firm Pearl & Dean and Tangibal Media to activate its free swimming campaign that aims to encourage families to go swimming with free swim vouchers.
The campaign includes cinema screen advertising, digital content and interactive floor graphics and postcards in 30 Pearl & Dean cinemas in the UK.
The campaign will run before family films throughout the Christmas period and into the New Year.
The energy provider launched the initiative to in September.
British Gas signed a six-year £15m sponsorship deal with British Swimming in March and signed Olympic gold medallist swimmer Rebecca Adlington as the face of its sponsorship in September.
Media planning was handled by Carat.