No Way to Treat a Lady is a 1968 American psychological thriller film with elements of black comedy, directed by Jack Smight, and starring Rod Steiger, Lee Remick, George Segal, and Eileen Heckart. Adapted by John Gay from William Goldman's 1964 novel of the same name, it follows a serial killer in New York City who impersonates various characters in order to gain the trust of women before murdering them.

Released in the spring of 1968, the film earned $3.1 million domestically, and received largely favorable reviews from critics, with praise for Steiger's performance and the film's blending of horror and dark humor. Segal was nominated for a BAFTA Award for Best Actor in a Supporting Role for his portrayal as Detective Moe Brummel.

A musical comedy adaptation by Douglas J. Cohen was produced in 1987, and revived Off-Broadway in 1996.