New claims emerged this month that the legendary Manchester band would reunite for a possible Glastonbury gig.
Now in an interview with NME for his debut solo album, Marr has joined his former bandmate Morrissey in categorically denying the rumours.
He said: "Everybody seems to know more about a Smiths reunion than I do. Those rumours are like a sport for everyone involved bar the people who were in the group 30 years ago. But it's not happening."
On the subject of his solo album, Marr admitted that while it is "late in the day" to release a solo debut, he "didn't want to be in someone else's band at this point".
He added: "In the past I might have been reluctant to stand up front, and I've been lucky enough to be in bands with great singers, so it wasn't necessary. But this is my band now, and the frontman in my band has to play guitar. I do both."
The 48-year-old has previously expressed regret that The Smiths no longer speak to one another and broke up amid such "bitterness".
Watch the video for The Smiths' 'The Boy with the Thorn in His Side' below: