AB5 may refer to: AB5 toxin Abelian category Analogue Bubblebath 5, an unreleased album by Electronica artist Richard David James AB5-type rare earth metal alloys used in nickel–metal hydride (NIMH) batteries SMC AB 5, a Wolf-Rayet star in the Small Magellanic Cloud AB-5, California Assembly Bill 5 (2019)