The pair met while filming a speed dating sketch for The Xtra Factor and have been texting each other ever since, according to Ireland's Evening Herald.
"The lads filmed a speed dating night with the girls from Little Mix. It was being shot for next weekend's Xtra Factor and it was all supposed to be a bit of a laugh," a source said.
"In the end they each had to choose one of the girls to go on a proper date with - and John chose Leigh-Anne. They just seemed to hit it off straight away and they've been texting each other all week since. He's totally smitten with her.
"Obviously John and Edward have been through this whole process before. John and Leigh-Anne have a lot in common and they seem to be really into each other."
Jedward's manager Louis Walsh previously revealed that he was planning to set up Jedward with Little Mix.
> Jedward party with Tara Reid in 'Wow Oh Wow' video - watch
Watch Jedward answering fan questions for Digital Spy below: