The pair have recorded a new track titled 'Loving You', which will get its radio premiere on Ken Bruce's BBC Radio 2 show tomorrow morning (July 2).
"I met Melanie at the Isle of Wight Festival last year," Cardle said. "I'm a big fan and I've always loved her voice.
"I had already started writing 'Loving You' and I thought with a few changes it could work perfectly as a duet. I'm really thrilled with the song and I can't wait for people to hear it."
'Loving You' - available to download on August 18 - serves as the first taster of his third studio album, which follows in October this year.
Cardle's debut album Letters entered at number two on the charts in 2011 and was certified platinum. Follow-up The Fire peaked at number eight.
Watch the video for his previous single 'Lately' below: