A source close to the player told Turkish-Football that the Black Eagles have struck a deal with Chelsea to sign Omeruo on a season-long loan deal. Besiktas have agreed a release clause in the contract and will have the option to sign the 22-year-old on a permanent basis.
The Istanbul giants are expected to cover his €1.1 million salary over the course of next season.
Omeruo was one of 26 Chelsea players loaned out last season and one of two who joined Turkish Super Lig sides on a temporary move. The Nigeria international is already familiar with Istanbul having played for city rivals Kasimpasa last season.
Besiktas won the league title last season and go into the 2016-17 campaign as one of the bookmakers favourites. Omeruo made 25 appearances in the Turkish Super League for Kasimpasa last season.