Dr. Williams is Professor of Clinical Pharmacy and Clinical Gerontology at the University of Southern California School of Pharmacy and the USC Davis School of Gerontology. He is also Director of the Education and Information Core of the USC Alzheimer Disease Research Center.

Dr. Williams received his Pharm.D. from the University of Southern California in 1977, after which he completed a residency in Geriatrics at the University of Southern California. He joined the faculty at USC in 1979. His responsibilities at the School of Pharmacy include a geriatrics clinical clerkship, teaching in an elective in Geriatric Pharmacy Practice, and directing a joint Pharm.D./Master of Science in Gerontology offered with the Davis School of Gerontology. In his clinical practice, Dr. Williams is responsible for monitoring drug therapy for elderly patients in a primary care geriatric setting; he has direct responsibility for managing drug therapy in select individuals. In addition to teaching student pharmacists, he also works with family medicine residents and medical students.

Dr. Williams is a certified geriatric pharmacist. He is a founding member and past chair of the Commission for Certification in Geriatric Pharmacy and is a past member of the Board of Directors for the California Geriatrics Society. Dr. Williams' professional affiliations include the American Society of Consultant Pharmacists, American Society of Health-System Pharmacists, American Association of Colleges of Pharmacy, American Geriatrics Society, and Gerontological Society of America. Dr. Williams is is an editor and chapter author for "Applied Therapeutics: The Clinical Use of Drugs", and is a member of the editorial board for "The Consultant Pharmacist".