Baby is an experienced centre but has been selected ahead of Francois Trinh-Duc, who will start on the bench after being called up during the week as cover for the injured Lionel Beauxis.
Young centre Mathieu Bastareaud will partner Yannick Jauzion as they look to contain the Welsh duo of Jamie Roberts and Tom Shanklin in Paris on Friday night.
Another change sees Morgan Parra come in for Sebastien Tillous-Borde, meaning a new combination at No.9 and 10 for, what is expected to be, the biggest test of the season for Les Bleus.
There is a return to the side for Sebastien Chabal while, up front, Sylvain Marconnet returns to international rugby to take his place in the front row.
Fullback Clement Poitrenaud has also been pushed on to the bench. Exciting starlet Maxime Medard will take over at 15 with Julien Malzieu returning on the wing.
France: 15 Maxime Medard, 14 Julien Malzieu, 13 Mathieu Bastareaud, 12 Yannick Jauzion, 11 Cedric Heymans, 10 Benoit Baby, 9 Morgan Parra, 8 Imanol Harinordoquy, 7 Fulgence Ouedraogo, 6 Thierry Dusautoir, 5 Sebastien Chabal, 4 Lionel Nallet (captain), 3 Sylvain Marconnet, 2 Dimitri Szarzewski, 1 Fabien Barcella
Replacements: 16 Benjamin Kayser, 17 Thomas Domingo, 18 Romain Millo-Chluski, 19 Louis Picamoles, 20 Sebastien Tillous-Borde, 21 Francois Trinh-Duc, 22 Clement Poitrenaud
