The 19-year-old only made his senior debut for Jurgen Klopp's team in September, coming off the bench in the dying embers of an EFL Cup third-round win over Leicester City.
With Andrew Robertson nursing a dislocated shoulder, Kostas Tsimikas is the only senior left-back available to Klopp, who has elected to rest the Greece international ahead of Sunday's Premier League fixture with Nottingham Forest.
As a result, Chambers is brought in to the backline for his full debut and is one of eight changes for the hosts from their 2-0 Merseyside derby win over Everton, as only Trent Alexander-Arnold, Diogo Jota and Ryan Gravenberch hold their places.
Caoimhin Kelleher, Joe Gomez, Joel Matip, Wataru Endo, Curtis Jones, Harvey Elliott and Darwin Nunez are also drafted into the Reds' first XI, while Ben Doak misses out once again due to the knock he sustained on international duty.
Meanwhile, Toulouse boss Carles Martinez has made one change from their win over LASK Linz on matchday two, sacrificing winger Cesar Gelabert for another defender in Logan Costa,
Liverpool: Kelleher; Alexander-Arnold, Gomez, Matip, Chambers; Jones, Endo, Gravenberch; Elliott, Nunez, Jota
Subs: Alisson, Jaros, Van Dijk, Diaz, Szoboszlai, Mac Allister, Salah, Gakpo, Tsimikas, Scanlon, McConnell, Quansah
Toulouse: Restes; Desler, Costa, Nicolaisen, Diarra, Suazo; Sierro, Casseres, Schmidt; Dallinga, Donnum
Subs: Dominguez, Lacombe, Genreau, Cesar, Kamanzi, Mawissa, Keben, Begraoui, Magri, Bangre