The 37-year-old reality star struck up a romance with Younes Bendjima earlier this month, just a week after he split from the 26-year-old British beauty.
And Jourdan - who has a six-year-old son, Riley, from a past relationship - is expected to be ''devastated'' by the news her 23-year-old former lover has moved on so quickly.
A source told The Sun newspaper: ''It's early days for [Kourtney and Younes] but they are enjoying each others' company.
''Younes had a great time with Jourdan but their busy schedules became too much and they decided to call it quits.
''He's told friends that he was the one who ended it.
''He's now quietly sparked a relationship with Kourtney and really fancies her. They aren't ready to go public but there's a real chemistry between them.
''They split just a week before he started to see Kourtney. Jourdan will be devastated by this.''
Kourtney met Younes - who began dating Jourdan in May 2015 - at Paris Fashion Week earlier this month.
The 'Keeping Up With the Kardashians' star has been single since splitting from Scott Disick, the father of her children Mason, six, Penelope, four, and Reign, 22 months, last July after nine years together.
But the former couple have repeatedly been rumoured to be planning to reconcile, though Kourtney recently insisted that won't happen.
She said: ''I mean, I'm so happy that Scott and I are getting along so well and that we're co-parenting, but I think hanging out with Scott without the kids...
''Scott can just take any little thing and run with it and think that like we're getting back together tomorrow.
''Right now, I can't even wrap my head around that idea, there's so much work that would be involved and I'm so not even there yet.''
Anima Animus is the third album from Siouxsie Sioux's The Creatures, released exactly 20 years ago today.
Edinburgh four-piece Gypsy Circus talk about their inspirations and their music in exclusive interview.
It doesn't take long to appreciate you are in the presence of rock music royalty when you are offered an audience with Paul McGuinness.
Happy Valentine's Day! Lots of couples will celebrating this cheesy AF but lovely day, and will most likely celebrate well into the night too.
As it's almost Valentine's Day, you'll be looking for that perfect romantic playlist to set a dinner date to, right?
'Lung Bread For Daddy', a phrase appropriated from a friend and referring to a request for a cigarette, is a multi-faceted journey through the life...
Andrew Bird has named his newest song after the Greek king Sisyphus, and he's release a new video with a similar sentiment.
Previously a duo, Honeyblood now comprises Stina Tweeddale on her own and she has returned with a brand new single and video, The Third Degree.