Ryan Moloney, who plays Toadie in the serial, told TV Week that actor Ian Smith will reprise his role "for a little bit".
He enthused: "I know that Harold is coming back for a little bit, I can't wait. I love Ian and it's good to work with an old friend."
Smith was last seen on Neighbours in February, having announced his retirement in August 2008. The star has since admitted that he "struggled" on the show.
Sam Clark, who portrays Ringo Brown, predicted a Harold comeback in October.