The Italian forward has moved to Anfield after just a single season in his native country and will link up with Reds boss Brendan Rodgers for the third time
The 21-year-old has signed a long-term deal with the Merseyside outfit and is set to link up with Brendan Rodgers for a third time after he worked under the Northern Irishman at Chelsea and Swansea City.
Borini netted nine goals in 24 Serie A appearances for Roma last season and earned a call-up to Italy's Euro 2012 squad, although he failed to feature for Cesare Prandelli's side at the tournament.
“The supporters are going to love him,” Rodgers told Liverpool's official website. "He's a big talent, 21 years of age, he scores goals, and his passion, focus and concentration is a very important part of his game - and a big part of what you want from a player.
“I've known him since he had just turned 16 years of age. We [Chelsea] took him in from Bologna when he was 16 and he progressed incredibly well as a young player to go on to play for the first team at Chelsea.
"It didn't work out in terms of he couldn't agree a contract, but before he left I took him on loan to Swansea and he made a big, big impression there and really helped us in our promotion charge that season.
“As I said, he's a goalscorer, but he's a multifunctional player who can play in a number of positions - and someone I believe has got great growth.”
Borini will wear the number 29 shirt.