Mentzer is a surname. Notable people with the surname include: Ethan Mentzer, member of The Click Five Frank Mentzer, American fantasy author John Thomas Mentzer, American marketing professor Mike Mentzer, American bodybuilder Ray Mentzer, American bodybuilder, brother of Mike Steven Mentzer, American politician in Pennsylvania Susanne Mentzer, operatic mezzo-soprano William C. Mentzer, aeronautical engineer See also Mentzer Building Mentzer index