While the GAR is predominantly made up of clones and the Separatists' of droids, both also have their share of non-clone, non-droid soldiers (e.g. Wookiees, Umbarans, Gungans, Mon Calamari, Quarren, etc.).
With organic lifeforms fighting alongside the Separatists' droids, has the Republic ever deployed droid forces to fight alongside the clones? I don't mean special cases like D-Squad or those re-programmed battle droids used in the mission to the Citadel. Rather, I'm looking for cases where droid forces are fielded en masse by the Republic against the Separatists, though not necessarily as the predominant force present on the Republic side. Has it ever happened before?
Answers from both canon and Legends welcome.