Slimani had six months remaining on his contract at the King Power Stadium but leaves early after making just one Premier League appearance for Leicester in the first half of the 2020/2021 season.
The 32-year-old arrived at Leicester City for a then club-record fee of £28m in the summer of 2016 from Sporting Lisbon but was unable to pin down a regular starting spot at the King Power Stadium, scoring just 13 goals in all competitions during his time at the club.
He was also loaned out to Newcastle United, Fenerbahce and AS Monaco in search of regular first team action.
Slimani’s arrival at Lyon will help to compensate for the loss of Moussa Dembele, who has joined Atletico Madrid on loan for the rest of the season.
"I am happy and proud to be at a big club like Lyon. I thank the president. When I was little, I have already come to the region, to Givors, to play tournaments with my team. I am a combative person who gives everything on the field,” Slimani said.
“I hope to bring my experience, my fighting spirit. I come to a team which is first in the championship, which plays well and scores goals. I want to help the team achieve its goals. I want to do something good here.
"Lyon is a big club which plays for the first places every year, which plays to participate in the Champions League.”
