Justin Lowe Quackenbush (born October 3, 1929)^[1] is a senior United States district judge of the United States District Court for the Eastern District of Washington.

Quackenbush was born in Spokane, Washington on October 3, 1929.^[2] His father, Carl Quackenbush, was a law student who eventually became a Superior Court judge in Spokane.^[3] Quackenbush received a Bachelor of Arts degree from the University of Idaho in 1951. He received a Bachelor of Laws from Gonzaga University School of Law, his father's alma mater, in 1957. He was an officer in the United States Navy from 1951 to 1954. He was a deputy prosecuting attorney in Spokane County, Washington from 1957 to 1959. He was in private practice in Spokane from 1959 until his judicial nomination. He was active in Democratic Party politics, regularly serving as the campaign manager for Tom Foley's successful Congressional election campaigns starting in 1964 for over a decade.^[4][5] Quackenbush also taught at Gonzaga University School of Law from 1961 to 1967, and was an active Mason.^[4]

On May 9, 1980, President Jimmy Carter nominated Quackenbush to the seat on the United States District Court for the Eastern District of Washington vacated by Judge Marshall Allen Neill. He was confirmed by the United States Senate on June 18, 1980, and received his commission the same day. Because Neill was the only judge in the district, and had died in October 1979, Quackenbush and fellow appointee Judge Robert James McNichols immediately faced a tremendous backlog of cases.^[6] Quackenbush served as chief judge from 1989 to June 27, 1995, when he assumed senior status.

• List of United States federal judges by longevity of service