Guitarist Marr and bassist Rourke will star together at the 28 January charity fundraiser for the Christie Hospital in Manchester, England. They last performed together as part of The Smiths in 1987.
The pair will appear at the Manchester Vs Cancer event with a host of local stars including New Order, Doves, Badly Drawn Boy, Primal Scream rocker and former Stone Roses bassist GARY 'MANI' MOUNFIELD, and Stephen Fretwell.
Marr says, "Andy and I go back a long way, since our school days. We have been hanging out and seeing each other and he told me about this project.
"I literally applauded him and said I wanted to get involved with it if he needed any help. It's a privilege to be part of it as I am aware of the work that Christie does.
"It's not the easiest thing getting something like this together because it needs to be done on a fairly big scale to have any significance so I think Andy is really brave.
"But who would refuse his offer to get involved? I mean, who could refuse it? You can't unless you are out of the country on tour. I made sure I was around and I'm looking forward to it - it will be a good night."