The 37-year-old has agreed a one-year contract, with the option for a further 12 months.
Brighton have announced the signing of James Milner on a free transfer from Premier League rivals Liverpool.
The former England international has agreed a one-year contract at the Amex Stadium, with the option for a further 12 months.
Albion head coach Roberto De Zerbi told his club’s website: “I’m very glad to welcome James to Brighton.
“He’s an excellent addition for us and I’m sure he will help to bring us to an even higher level.”
Milner, who won 61 international caps between 2009 and 2016, began his career with Leeds and has also played for Newcastle, Aston Villa and Manchester City.
The 37-year-old won the Premier League, Champions League, FA Cup and Carabao Cup during eight years at Anfield.
He will join Brighton following the expiration of his Reds contract on June 30 and add experience to De Zerbi’s squad ahead of the club’s maiden Europa League campaign.
Seagulls technical director David Weir said: “His experience speaks for itself with the amount of games he has played and the trophies he has won throughout a decorated career.
“These games include European competition, which will be of huge value to us as we embark on our first season in Europe.”
Milner is currently third in the list of all-time Premier League appearances with 619, behind Gareth Barry (652) and Ryan Giggs (632).
The veteran midfielder, who can also operate at full-back, is Brighton’s second signing of the summer following the club-record arrival of Brazilian forward Joao Pedro from Watford.