The highly rated 19-year-old helped Genk win the Belgian title last season and Chelsea are understood to have been tracking him for the past few months and look set to beat Atletico Madrid to the signing.
Thierry Courtois, the players father and agent, confirmed a deal was close and he expected it to go through on Tuesday.
'He [Thibault] was in in Chelsea last week,' he said.
Soon to be a Blue: Teenage goalkeeper Thibaut Courtois is close to a move to Chelsea
'I think Chelsea and Genk have reached an agreement. Tuesday we will come and talk about the transfer.'
Chelsea are reportedly happy to let Courtois return to Genk on loan, and his father admitted this was an option but he rubbished any claims he could sign a new deal with the Belgian club.
'Maybe Chelsea will lend Thibaut to Genk, but a contract extension does not interest us anymore,' he added.
Chelsea are still understood to be keen on making a double swoop on Genk, as talks over midfielder Kevin de Bruyne also continue.
Keen on a move: Kevin De Bruyne wants to join Chelsea from Genk
If Chelsea do sign De Bruyne then they look set to also send him out on loan, but to but to Genk's rivals Anderlecht, which would also have helped their continued pursuit of Romelu Lukaku.
But, Genk are not keen to allow De Bruyne to be loaned to any other Belgian club should he be sold.
And Lukaku says he is happy to stay at Anderlecht, should his move to the Premier League club not happen.
'Occasionally you might yearn for something new, but for now I sit here very well. We'll see where it goes,' he said.
But he still admits a move to England is his dream, adding: 'I would really like a top transfer and I have always wanted to go to England.'
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Source: Daily Mail
Source: Daily Mail