The former Guns N' Roses star will take to the stage with the Scottish group on 7 November (14) for an intimate gig which members of Biffy Clyro have dubbed a "dream come true".
A Tv crew will film the show as part of Mtv Music Week, a series of events spread over the week prior to the awards show.
In a statement on Mtv's website, Slash wrote, "Can't wait to bring the rock back to Mtv and World Stage in Glasgow on Nov 7!"
A message from Biffy Clyro reads, "Four words: Biffy!! Slash!! Mtv!! Glasgow!! Three words: dream come true!!"
The European Music Awards, hosted by Nicki Minaj, take place on 9 November (14) in Glasgow.