The Italy Under-21 international, who turns 20 next week, rejected interest from Lazio, Parma and Juventus to join Swans` quest for promotion to the Barclays Premier League.
Borini trained with the squad on Thursday morning and he is now waiting for the paperwork to be finalised for him to be included in the squad for Saturday's npower Championship clash with Nottingham Forest at the Liberty Stadium.
Boss Brendan Rodgers told the club`s official website: "I'm delighted with the signing. He's a player I tried to get earlier in the season but because of complications with his contract at Chelsea and the fact he was in and around the first team, he didn't get permission to go out on loan.
"He's a young player with great potential. He's got intensity, passion and a natural goalscoring ability. I worked with him in Chelsea's youth and reserve team and I firmly believe he will help us a great deal during the run-in."
Borini, out of contract at the end of the season, joined Chelsea from Bologna in the summer of 2007 and has made eight first-team appearances.
Source: PA
Source: PA