Borderline is a 1950 American crime film noir directed by William A. Seiter and starring Fred MacMurray and Claire Trevor.

[2] Pete Ritchie (Raymond Burr) runs a narcotics smuggling operation to the US from Mexico, which the Los Angeles Police Department and the US federal government have unsuccessfully tried to stop.

As a last resort, Madeleine Haley (Claire Trevor), an LAPD officer and former OSS operative, is sent undercover to Mexico to charm her way into Ritchie's confidence.

Leonard Maltin's TV Movies & Video Guide (1989 edition) slightly raises the rating to 2½ stars (out of 4) and concludes that "Trevor and MacMurray work well together as law enforcers each tracking down dope smugglers on Mexican border, neither knowing the other isn't a crook".

By the time of the third edition (2015) of Maltin's Classic Movie Guide, the rating had been lowered to the Scheuer level of 2 and the write-up changed to "[O]dd thriller-comedy in which L.A. cop Trevor attempts to gather evidence against wily drug smuggler Burr while mixing with tough guy MacMurray in Mexico.