The 27-year-old Belgian international Origi has joined Milan as a free agent after his contract was registered with the Italian top flight, although the club are yet to announce the move.
Origi arrives at the Serie A team after not having played enough matches to trigger an extension to his contract with Liverpool.
He has reportedly signed a four-year deal which will net him four million euros ($4.23 million dollars) a season.
He was largely a bit-part player at Liverpool but scored vital goals over his eight years on Merseyside which made him a favourite of fans and manager Jurgen Klopp.
Those strikes include two in an astonishing comeback against Barcelona in the Champions League semi-finals in 2019, and the second is that year’s final as Liverpool lifted their sixth European Cup against Tottenham.
Origi made 176 appearances for the Reds after arriving in 2014, scoring 41 times.
He has been capped 32 times for his country, but all three of his international goals came in 2014.
Milan have brought in Origi to bolster a forward line which struggled for goals despite winning last season’s thrilling Serie A title race.
Coach Stefano Pioli’s two veteran centre-forwards — Olivier Giroud and Zlatan Ibrahimovic — netted just 19 times between them in the league.
Last month Ibrahimovic was ruled out for up to eight months following knee surgery, having missed large chunks of Milan’s title charge with injury.
Two days after the announcement of Ibrahimovic’s operation director and club legend Paolo Maldini said the 40-year-old intended to continue playing, and Italian media report that Milan are ready to extend his contract by another year.