The Patient in Room 18 is a 1938 American mystery romantic comedy film directed by Bobby Connolly and Crane Wilbur.

The screenplay written by Eugene Solow and Robertson White was based on a 1929 novel of the same name by author Mignon G. Eberhart.

In the hospital, a wealthy patient and the head doctor are both murdered, and valuable medicinal radium is stolen.

Private investigator Lance O'Leary suffers a nervous breakdown from being unable to solve a case and his doctor has him hospitalized for rest.

The first night there a murder takes place as wealthy Mr. Warren is killed in his room and $100,000 worth of medicinal radium on his chest is stolen.