D. O. Dillavou

D. O. Dillavou (May 1, 1936 – October 29, 1968) was an American attorney and politician. Born in Deadwood in South Dakota, he graduated from Spearfish High School in 1954, where he played basketball. He then received a Bachelor of Science from the University of South Dakota in 1958. Dillavou earned his law degree from the university's School of Law, and he began practicing law a few months later after his admission into the state bar. In July 1961, he was appointed as the state's attorney of Lawrence County, following the resignation of Larry D. McDonald. Dillavou was re-elected to the position twice, in 1962 and 1964. Throughout his lifetime, Dillavou was an avid sportsman.

In March 1968, Dillavou announced his campaign for the South Dakota House of Representatives as a member of the Republican Party. He won the primary alongside James D. Jelbert. On October 29, 1968, Dillavou was mortally wounded in a traffic collision while driving along Interstate 90; he died a few hours later. Because ballot papers for the general election had already been printed, Dillavou's name was not removed from them. He ended up winning the election posthumously, placing second. In January 1969, Robert F. Ruth was appointed to fill Dillavou's term.