Affair in Reno is an uneven Republic adventure from the later phases of the studio's history. Doris Singleton, usually cast as the heroine's next door neighbor or best friend (she's Caroline Appleby in the "Harpo Marx" episode on I Love Lucy), is here seen as a smart-lipped private eye. She comes to Reno on a case, and falls in love with publicity agent John Lund. But nothing dissuades her from her mission to get the goods on suspected crook John Archer. Affair in Reno doesn't have much in the way of production values, but compensates for this with an emphasis on comedy, especially whenever Doris Singleton has to pose as someone she's not.
~ Hal Erickson, All Movie Guide