The Chilean is without a club after his contract with Inter Milan was terminated this summer.
However, Sanchez could be plying his trade in Ligue 1 next season.
This was revealed by transfer expert, Fabrizio Romano, on Thursday morning.
“Olympique Marseille will be in direct contact with Alexis Sanchez agents in the next days, as termination of the contract with Inter is agreed and will be signed soon,” Romano tweeted.
Sanchez joined Inter from Manchester United on a free transfer in 2020.
The 33-year-old has scored just 20 goals and provided 23 assists in 108 games.