Dew was born in Sumner, Washington, and began his acting career in the mid-1930s, appearing in small film roles.
His first film roles of any substance were as Captain Kendall in Military Academy (1940) and Henchman French in Dude Cowboy (1941).
Many of the pictures he made with Universal during the 1940s were with Rod Cameron, such as Trigger Trail (1944) and Renegades of the Rio Grande (1945).
His last film was Pagan Island (1961) and his television credits included appearances on Annie Oakley, Buffalo Bill, Jr., and Hawaii Five-O.
His work as a director is most associated with the television show Sergeant Preston of the Yukon, for which he directed 40 episodes.