Kelly picked up a knee injury in the November international against Australia after he had come on as a replacement for Denis Hickie.
Kelly's return means that Munster's seasonal leading try-scorer, Mossie Lawlor slips to the bench in the only change to the side from the one that started against Viadana a week ago.
James Blaney returns to the replacements at the expense of John Fogarty and Colm McMahon makes way for Lawlor.
Meanwhile, Ulster have also made just one change for their trip to Biarritz with Adam Larkin continuing in the centre having come on as a replacement for Ryan Constable in the opening minutes of last Friday's game in Ravenhill. With Shane Stewart ruled out through injury, Jan Cunningham has been called onto the bench and coach Alan Solomons will bring David Spence the Queens University scrum-half to France as emergency cover.
Ulster (v Biarritz Olympique, Saturday, Parc des Sports Aguilera). Bryn Cunningham; James Topping, Adam Larkin, Johnny Bell, Scott Young; David Humphreys; Neil Doak; Justin Fitzpatrick, Matt Sexton, Robbie Kempson; Gary Longwell, Jeremy Davidson; Warren Brosnihan, Neill McMillan, Andy Ward (capt)
Replacements: Simon Best, Paul Shields, Mark Blair, Tony McWhirter, Kieran Campbell, Jan Cunningham, Sheldon Coulter.
Munster (v Viadana, Saturday, Stadio Luigi Zaffanella). J Staunton: J Kelly, M Mullins, J Holland, A Horgan: R O'Gara, P Stringer; M Horan, F Sheahan, J Hayes; P O'Connell, D O'Callghan; J Williams (capt), A Quinlan, A Foley.
Replacements: J Blaney, S Kerr, M O'Driscoll, E Halvey/D Leamy, M Prendergast, K Keane, M Lawlor.