The striker arrived Sunday morning at the Ramon Sanchez-Pizjuan and, after undergoing medical tests, met with club president Jose Castro to sign the contract that will keep him in Andalusia for three years.
A Celta legend after making 100 appearances for the club, Nolito moved to the Premier League in 2016 but failed to find his footing with Pep Guardiola's side and returns to La Liga after playing just 775 minutes in league play.
He started off strong in England, scoring three goals in his first three matches, but cooled considerably and hadn't found the back of the net in league play since a December defeat to Leicester City.
The club hopes his arrival will help offset that of Vitolo, who is headed to Atletico Madrid after completing a loan spell because of Atleti's transfer ban.
Nolito should have great rapport with Sevilla coach Eduardo Berizzo, as the two worked together for two years at Celta. Nolito and Argentine defensive midfielder Guido Pizarro were reportedly Berizzo's two top targets in the market, and the coach will have both of them in his employ in the upcoming season.
Nolito now becomes the fourth summer signing for Los Rojiblancos, with the team also set to count on Ever Banega, Pizarro and Colombian forward Luis Muriel.
The 30-year-old is set to travel to Madrid to arrange his travel documents for a trip to Japan, where he'll arrive Tuesday to join up with the team for their preseason.