Graham Potter was appointed as Chelsea's new manager on Thursday after leaving Brighton to replace the sacked Thomas Tuchel at Stamford Bridge.
Potter has agreed a five-year contract to take charge of the Premier League club, who praised his "progressive football and innovative coaching".
He led Brighton to a ninth-place finish last season and took them up to fourth in the table this term, while demanding entertaining and tactically astute performances from his players.
"I am incredibly proud and excited to represent Chelsea FC, this fantastic football club," said the Englishman.
"I am very excited to partner with Chelsea's new ownership group and look forward to meeting and working with the exciting group of players and to develop a team and culture that our amazing fans can be proud of. I would also like to place my sincere thanks to Brighton and Hove Albion for allowing me this opportunity."
Chelsea chairman Todd Boehly, who axed Tuchel just seven games into the new season, believes Potter will fit perfectly with his vision for the future at Stamford Bridge.
Boehly-led consortium completed its takeover of the club earlier this year, bringing to an end Roman Abramovich's reign.