The club’s director, Marina Granovskaia, told their official website:
“This was not an easy deal for us to do because of the numerous parties involved, but we are delighted we were able to make it happen.”
Higuaín has signed for Chelsea on a six-month loan deal, with an option to buy for £32.5m in the summer.
The 31-year-old will wear the no.9 shirt.
Blues boss, Maurizio Sarri, has been desperate to bring in a new frontman, with Alvaro Morata now expected to complete a loan move of his own to Atletico Madrid.
Higuain enjoyed his most prolific season ever under Sarri at Napoli and is eager to be reunited with the Italian.
Chelsea however failed to register Higuain in time for Thursday’s Carabao Cup semi-final second leg against Tottenham, after the deadline passed at midday on Wednesday.