Born in O'Neill, Nebraska, Whelan received a Bachelor of Arts degree from San Diego State University in 1928 and both a Bachelor of Laws and a Juris Doctor from the UC Berkeley School of Law in 1932.

He was an Assistant United States Attorney of the Southern District of California from 1935 to 1939.

[1] Whelan was nominated by President Lyndon B. Johnson on August 17, 1964, to a seat on the United States District Court for the Southern District of California vacated by Judge Leon Rene Yankwich.

He was confirmed by the United States Senate on September 15, 1964, and received his commission the same day.

Whelan served in that capacity until his death on August 22, 1991, in Palm Desert, California.