The striker becomes manager Sean Dyche’s first new addition of the transfer window, and joins on a three-and-a-half year deal.
Having initially moved to them on loan, Barnes made 141 league appearances for the Seagull’s, scoring 42 goals and was part of the side that won promotion to the Championship under Gus Poyet by clinching the League One trophy.
The move continues the resurgence of the 24 year olds career, who spent four loan spells across the Conference and League Two before moving to Brighton from Plymouth Argyle.
He will go straight into the Burnley squad for tomorrow’s trip to Championship strugglers Yeovil Town, where the Clarets will be hoping to keep in touch with league leaders Leicester City.
Barnes can be backed at a price of 11/2 to open the scoring against the side who are second from bottom of the division.