The La Liga champions have been heavily linked with the 21-year-old stopper in recent months, and are thought to have made contact with the Blues ahead of an end of season move.
Courtois has been a Chelsea player since 2011, but is yet to make an appearance for the club.
Upon his arrival from Genk, the Belgian was immediately loaned out to Atletico Madrid, where he has remained ever since.
Courtois has developed into one if the Vicente Calderon side’s top performers, and is valued highly in the Spanish game.
Barca are thought to see him as an ideal replacement for Victor Valdes, with their longstanding glovesman ready to quit the club at the end of the current campaign in search of a new challenge.
Chelsea are far from keen to let their starlet go, but the player himself is desperate to play regularly.
With Petr Cech established as Jose Mourinho’s number one ‘keeper he may have to wait, which could open to door for a switch.
The London club will want at least £17m for their man, which may see Barca turn their attention to Liverpool’s Pepe Reina.