Manchin was born in Farmington, West Virginia, in 1947, the second of five children of Mary (ne Gouzd) and John Manchin. His grandparents were Italian and Czechoslovakian immigrants.
Dr. Manchin II graduated from the West Virginia College of Osteopathic Medicine in 1978. He works in Farmington, WV and 1 other location and specializes in Family Medicine. Dr. Manchin II is affiliated with Fairmont Regional Medical Center.