Two on a Guillotine is a 1965 American horror film produced and directed by William Conrad and starring Connie Stevens. The screenplay by John Kneubuhl and Henry Slesar is based on a story by Slesar. The movie would be the first in a series of low-budget suspense dramas made by Warner Bros in the vein of the successful William Castle films, and was followed by My Blood Runs Cold and Brainstorm, both also released in 1965 with Conrad as director. A fourth movie, The Thing at the Door, was proposed, but never made.