Ibrahimovic was widely expected to finalise his transfer on Wednesday, with the Ligue 1 club announcing a press conference for the afternoon.
And the Swedish international has ended the speculation by signing a three-year deal with PSG after a fee reported to be €20million was agreed.
The 30-year-old will now link back up with former Milan team-mate Thiago Silva, who joined PSG on Saturday.
Ibrahimovic, who had a contract with Milan until June 2015, was Serie A's top scorer last season, netting 28 goals as I Rossoneri finished runners-up to Juventus.
The former Barcelona, Juve, Inter Milan and Ajax striker is the latest big-money signing to arrive in the French capital as PSG bid to win the Ligue 1 title for the first time since 1994, after finishing runners-up behind Montpellier last season.