I think the best answer is always a positive one. You don't have to go into detail about your shituation at the former workplace. Just say you are eager for new challenges, a place where you could learn new skills, expand your knowledge base, etc. In essence you want to stress that you are excited about this new job opportunity and hope to be given the chance to work hard and advance in your career. Don't mention the supervisor problem. Don't mention the supervisor at all for that matter if you don't have to. It's a red flag if you bark about your boss. The new employer may interpret problems with the boss as a potential problem with you - possibly a lack of interpersonal skills and a negative attitude to boot. Employers want team players. If you are asked a direct question about the boss, you can honestly say you had different working styles. Then use that opportunity to highlight your skillset and the strengths you brought to the job. You can also say you learned a lot from your supervisor (in other words you learned that it's best to get the hell out of Dodge). I would use someone in Human Resources as a reference or another coworker in your department. Don't use the Director unless you left on really good terms. If the Director was treating you and others poorly, that person has a serious respect issue and can't be trusted to give a good reference. That person is unprofessional. He or she should be in therapy, not management. Happy job hunting.