N-R
| Title | Director | Cast | Genre | Notes |
|---|---|---|---|---|
| Never Say Goodbye | Jerry Hopper | Rock Hudson, Cornell Borchers | Romance | |
| Nightmare | Maxwell Shane | Edward G. Robinson, Kevin McCarthy | Film Noir | United Artists |
| On the Threshold of Space | Robert D. Webb | Guy Madison, John Hodiak | Science fiction | |
| Once Upon a Honeymoon | Gower Champion | Virginia Gibson | Musical | Short subject |
| The Opposite Sex | David Miller | June Allyson, Joan Collins | Musical | MGM; remake of The Women |
| Our Miss Brooks | Al Lewis | Eve Arden, Gale Gordon | Comedy | Warner Bros.; film version of TV series |
| Over-Exposed | Lewis Seiler | Cleo Moore, Richard Crenna | Film Noir | Columbia Pictures |
| Pardners | Norman Taurog | Dean Martin, Jerry Lewis | Comedy | 15th Martin and Lewis film |
| Patterns | Fielder Cook | Van Heflin, Everett Sloane | Drama | written by Rod Serling |
| The Proud and Profane | George Seaton | William Holden, Deborah Kerr | Drama | Paramount Pictures |
| The Proud Ones | Robert D. Webb | Robert Ryan, Virginia Mayo | Western | |
| Rabbitson Crusoe | Friz Freleng | Bugs Bunny | Animation | Warner Bros. |
| The Rainmaker | Joseph Anthony | Katharine Hepburn, Burt Lancaster | Drama | Paramount Pictures |
| Ransom! | Alex Segal | Glenn Ford, Donna Reed | Drama | MGM |
| The Revolt of Mamie Stover | Raoul Walsh | Jane Russell, Richard Egan | Drama | 20th Century Fox |
| Rock Around the Clock | Fred F. Sears | Bill Haley & His Comets | Musical | |
| Rumpus in the Harem | Jules White | Three Stooges | Comedy | Columbia Pictures |
| Run for the Sun | Roy Boulting | Richard Widmark, Trevor Howard | Thriller | Remake of The Most Dangerous Game |
Read more about this topic: List Of American Films Of 1956