25-year-old Keita was linked with Fiorentina recently, but the winger will play for Sampdoria in the 2020-21 season.
Sampdoria will have the option to buy Keita when his loan term is up next summer, Gianluca Di Marzio reports.
The Senegal international could arrive in Genoa tomorrow and may even debut against Juventus on Sunday.
Keita joined Monaco from Lazio for €30m in 2017 only to return a year later on loan at Inter.
Inter did not not use their option to buy Keita, who returned to Monaco and made 29 appearances last season.