Jim was born and raised in San Diego. He played football at Point Loma High School graduating in 1956, then played football at San Diego City College in 1957-58, and at San Diego State University in 1959-60. Jim officiated football for 43 years at all levels, from youth football to NCAA Division III. As an active member of the San Diego County Football Officials Association, Sibbet has served as President, Board Member, Assignment Secretary and is currently the instructor for the 2nd year probationary class.
