Most hydration backpacks are highly versatile, so yes. The hydration sleeve can even be multi-purpose if the bladder is removed; if it’s an insulated sleeve, it could serve as a cooler for food or drink. Most hydration packs also have side pouches to potentially carry water bottles, too.
However, there are some important considerations: temperature extremes might make insulation of the hydration sleeve or hydration tube essential; also, one should use common sense when considering the amount of carrying volume needed.