William Solon Dellinger (born March 23, 1934) is a retired American middle-distance runner, and track and field and cross country coach.

Upon retirement from competition, Dellinger took a position as the assistant coach to Bill Bowerman for the Oregon Ducks track and field team.

In his 25 years of coaching, Dellinger's men won five NCAA titles, achieved 108 All American honors, and had a 134–29 meet record.

Dellinger also coached many post-collegians including Olympians Mary Decker, Bill McChesney, Alberto Salazar, Matt Centrowitz, Don Clary, and many others.

[1] Dellinger retired from the University of Oregon in 1998 [4] and would later join his mentor, Bill Bowerman, as an inductee in the National Track and Field Hall of Fame in 2001.