They will take part in the last ever pair of celebrity shows, with questionmaster Chris Tarrant signing off with an additional episode looking back at his years of hosting the show next month
The presenter said: "I've loved the buzz of it and will miss the sheer drama of watching someone, literally eyeball to eyeball, agonising over whether or not they know an answer and are brave enough to go for it, with a huge amount of money at stake."
In the penultimate edition to be screened on Tuesday, Russell Kane teams up with Gloria Hunniford, Frank Skinner partners Adrian Chiles, and singer Alexandra Burke joins designer David Emanuel.
And in the final programme on February 4, track cycling star Sir Chris will appear with comic Kevin Bridges, James Nesbitt is paired with Dom Joly and Riley will be reunited with fellow Strictly Come Dancing Contestant Dave Myers of Hairy Bikers fame.
Tarrant will look back over his years on the ITV show with a programme Who Wants To Be A Millionaire? Chris's Final Answer! to be screened on February 11.
ITV announced last year that it was to drop the series which launched in 1998 and became a global hit.
Tarrant joked: "I'm not sure I'll miss someone shouting "hey Chrissie, do you wanna phone a friend?" at me out of their car window or across a busy street. I genuinely think it's happened to me every day since September 1998. It even happened last year when I was filming in Sierra Leone."