The actor, who plays Jason Grimshaw in the ITV1 soap, said he would love her character Becky McDonald to make a cameo appearance on the Cobbles.
"I'd like to see Becky's return some time, I miss that character very much and I miss the person very much, Katherine, I think if she ever came back as a guest appearance it would make my day," Thomas told MSN.
He also told the website that he has a great relationship with co-star Sue Cleaver, who plays his on-screen mum Eileen.
"We're quite protective over each other and we look after each other. She brought me up in a way," he said. "It's been great to have such a great mum on and off screen."
Speaking of younger brother Adam, who stars in Emmerdale as Adam Barton, Thomas added: "I'm very proud of him. It's great that me and Adam are both working in soaps. To see him doing it as well is great.
"There's never any rivalry between any of the soaps. We're all doing the same job, we're all very close and get on quite well. I've got a lot of friends from different soaps."
Kelly quit Coronation Street last year to pursue other projects. Her final scenes aired in early 2012. Get the Inside Soap magazine on your iPhone or iPad