Most indoor cats never need a bath, they clean themselves pretty well. In the few cases where a bath is needed (accidents happen, cat got very dirty outside, or similar): don't use any human soaps, try to only use water, as cats have a natural scent that they build over time washing themselves, and perfumes work against that. Also, they will lick it up later. Soap is not a good thing to ingest!

Especially if you have multiple cats, a cat smelling very differently can lead to fights.