The former Barcelona starlet joins the San Siro outfit on a one-year loan deal after spending just a single season with the Giallorossi
The Spaniard departs the side from the capital after just one season, having signed with the 2011 Serie A champions on a one-year loan.
The former Barca player successfully completed his medical on Wednesday morning and will be unveiled on Thursday as the latest addition to Massimiliano Allegri's Milan squad.
The Rossoneri turned their focus towards signing the 22-year-old earlier this week after their bid to sign Real Madrid's Kaka fell through.
Last season Bojan made 33 appearances for Roma, scoring seven goals.
Meanwhile, Barcelona have announced on their official website that Bojan's move to San Siro will not affect their prior agreement that the player would move back to Camp Nou next summer.
"Barcelona were informed of the transfer of Bojan Krkic from AS Roma to AC Milan. The player will join the Rossoneri on loan for one season," the statement read.
"The agreement between the two Italian sides does not affect the prior agreement between AS Roma and Barcelona."