Born in Keytesville, Missouri, Collet was in the United States Army Air Corps from 1917 to 1918, and read law in 1920.
He then served as assistant counsel to the Missouri State Highway Department from 1930 to 1933.
His service terminated on July 11, 1947, due to his elevation to the Eighth Circuit.
[2] Collet was nominated by President Harry S. Truman on April 30, 1947, to a seat on the United States Court of Appeals for the Eighth Circuit vacated by Judge Kimbrough Stone.
His service terminated on December 5, 1955, due to his death in Kansas City, Missouri.