The Frenchman is coming on the back of an impressive season in Ligue 1.
Other reports claim that the French goalkeeper has completed his medicals ahead of a five-year deal with Rossoneri.
The 25-year-old will arrive at San Siro after winning the Ligue 1 title with LOSC Lille, who ended the dominance of PSG. Perhaps, Maignan was instrumental in the success, putting on some impressive displays between the sticks, which saw him garner more clean sheets than any other keepers in Europe’s top leagues.
Having spent his youth ranks with Paris Saint-Germain and the formative years with their U-23 side, Maignan moved to Lille in 2015. He is also one of the goalkeepers called up by the France national team for Euro 2020.
Maignan is expected to slot in the starting 11 straight away, taking the place of Gianluigi Donnarumma, who would leave Milan on a free transfer.
The young Italian keeper’s future had been subject to debate as his contract was set to expire this summer, and he was also said to be unhappy with renewal offers.
However, Milan director and former player Paolo Maldini cleared the air on Donnarumma’s future, confirming that he would leave as a free agent this summer.
Maldini said: “Gigio was a leader and often the captain. People sometimes don’t realise what it means to be a professional; it means you must be ready to change club.
It’s difficult to accept, I realise, but it’s also increasingly difficult to see a career in one team. We must respect those who gave so much to Milan and remember Donnarumma did not lack respect for us.
It can happen that, at times, you have to take different paths. I can only wish him the best.”
The 22-year-old has been strongly linked with a move to Barcelona and Juventus.