Trailin' West (UK title: On Secret Service) is a 1936 American Western film directed by Noel M. Smith and written by Anthony Coldeway and starring Dick Foran, Paula Stone, and Wild Bill Elliott.

In 1864, President Abraham Lincoln sends an undercover agent, Lt. Red Colton, to fictional Kent City to apprehend Curly Thorne and his outlaws who are disrupting Union gold shipments.

Nearing the town, Red stops the robbery of a stage line, and meets passenger Lucy Blake.

Red accepts a job as a card dealer at Thorne's bar where Lucy works as a dance hall girl.

Lucy erroneously believes Red as "John Madison" is involved in this plot and reports it to Colonel Douglas.