AB5

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)