The Bells of St. Mary's (1945) is an American musical comedy-drama film, produced and directed by Leo McCarey and starring Bing Crosby and Ingrid Bergman. Written by Dudley Nichols and based on a story by McCarey, the film is about a priest and a nun who, despite their good-natured rivalry, try to save their school from being shut down. The character Father O'Malley had been previously portrayed by Crosby in the 1944 film Going My Way, for which he won the Academy Award for Best Actor. The film was produced by Leo McCarey's production company, Rainbow Productions.

The unconventional Father Charles "Chuck" O'Malley is assigned to St. Mary's parish. Upon arriving at his quarters, the housekeeper warns him that their last priest prematurely aged while there. His duties include overseeing a nun-run, run-down inner-city school.

The first time Father O'Malley has been responsible for a school, he's nervous he must address the large group of nuns. While he's trying to make some opening remarks, they continually giggle which disconcerts him. Finally he discovers a playful kitten was upstaging him.

Getting a tour by Sister Superior Mary Benedict, O'Malley is to recommend whether or not the school should be closed and the children sent to another school with modern facilities. However, the sisters feel that God will provide for them and put their hopes in Horace P. Bogardus, a businessman who has constructed a modern building next door to the school on land he had bought from them. They are hoping he will donate it to them.

Father O'Malley and the dedicated but stubborn Sister Benedict both wish to save the school, but their different views and methods often lead to disagreements. The Father has admitted eighth-grade student, Patsy of Syracuse, New York, whom the parish has taken in while her mother attempts to get back on her feet. He is told that, although she had been married to the father, the musician had gone to Cincinnati but broke his promise to send for her.

When Patsy falls behind, Benedict questions O'Malley, concerned about her background. Respecting the mother's privacy, he deflects her questions.

They have another clash involving student Eddie, who is being bullied by another, newer student. Concerned, the former tomboy although at first teaching the children to turn the other cheek, decides to teach him boxing from a manual.

The Father "coaches" Patsy to be original in a paper for Sister Benedict, earning her a high mark. When the bully next trips Eddie, the Sister coaches from the sidelines, and not only does he hold his own, but he makes peace and offers friendship to him.

They plant a seed of an idea to Mr. Bogardus. After being shown around the building, they point out that his donation of the building to the school would be his great legacy. Later, when he gets worked up over another costly delay, his doctor points out the stress is bad for his heart.

Father O'Malley surprises Patsy's mother with a reunion with her estranged husband. He found him via the musicians' union, as he's a musician. They reconcile, surprising Patsy when she sees them kiss, who had come to show her mother her graduation dress.

At her exams, Patsy is upset. The Father visits Sister Benedict, who tells him her marks are too low to pass. When he tries to convince her to pass her anyway, they butt heads. He points out the self-esteem issues that come with failing and talks about a very successful business owner in town who had had difficulties at school.

Mr. Bogardus, convinced by his doctor that doing so will prolong his life, starts to do selfless acts. He gives a blind beggar money, helps an older woman to get on the bus, adopts a homeless dog and ultimately gives the sisters his building for the school.

Patsy is finally introduced to the man she had seen kissing her mother, her father. She admits to sister Benedict that she intentionally failed her exams so she could be held back a year and stay with Sister Benedict. Patsy demonstrates knowing the material that was on the exam. Knowing this, Sister Benedict allows Patsy to graduate.

Preparations are being made with getting the new building set, and Sister Benedict enthusiastically oversees setting up the new facility. Unfortunately, Father O'Malley has to break the news that her placement has changed.

As Sister Benedict contracted tuberculosis, the physician recommends to Father O'Malley that she be transferred to a dry climate with non-parochial duties, but without telling her the reason. She assumes the transfer is because of her disagreements with O'Malley and struggles to understand the reasons for the path set out for her. Just before Sister Benedict departs, Father O'Malley reveals the true reason for her temporary transfer, and she then leaves happily, looking forward to her return.

The film holds an 85% rating on Rotten Tomatoes based on 20 reviews, with an average rating of 7.2/10. Bosley Crowther of The New York Times felt that the film was too similar to Going My Way, and "although a plenteous and sometimes winning show, lacks the charm of its predecessor—and that comparison cannot be escaped." The reviewer for Variety wrote: "Picture is packed with many simple scenes that tug at the heart and loosen the tears as directed by McCarey and played by the outstanding cast." Harrison's Reports commented: "As in Going My Way, which he also wrote, produced, and directed, Leo McCarey has proved again that great pictures do not require pretentious stories ... The acting of the entire cast is excellent. Crosby delights one with his ease and natural charm, and Miss Bergman will undoubtedly rise to new heights of popularity because of the effective way in which she portrays her role." John McCarten of The New Yorker wrote derisively: "Mr. McCarey seems to view the Roman Catholic Church, which is quite a formidable and venerable organization, as a kind of settlement house where good works and jollity provide a lively substitute for religion ... Everything, of course, turns out quite happily, except, perhaps, for those captious souls who regard religion as an adult matter."

The Bells of St. Mary's placed fourth on Film Daily's year-end nationwide poll of 559 critics naming the best films of 1946.

The film earned receipts of $8 million in North America during its initial run, making it the highest-grossing movie of 1945 in the USA.

It made a profit of $3,715,000, making it the most profitable film in the history of RKO. Adjusted for inflation, it is considered the 57th highest-grossing film of all time.

• "Aren't You Glad You're You?" (Jimmy Van Heusen / Johnny Burke) sung by Bing Crosby
• "Adeste Fideles" sung by Bing Crosby and children's choir
• "In the Land of Beginning Again" (George W. Meyer / Grant Clarke) sung by Bing Crosby
• "O Sanctissima" sung by Bing Crosby
• "It's Spring" ("Vårvindar friska" in Swedish) sung by Ingrid Bergman
• "The Bells of St. Mary's" sung by Bing Crosby and choir

Bing Crosby recorded four of the songs for Decca Records and these were issued as singles as well as a 2-disc 78 rpm album titled Selections from The Bells of St. Mary's. "Aren't You Glad You're You" was in the Billboard charts for nine weeks with a peak position of #8. "In the Land of Beginning Again" and "The Bells of St. Mary's" both charted briefly also. Crosby's songs were also included in the Bing's Hollywood series.

At the Academy Awards, it won for Best Sound Recording (Stephen Dunn). It was nominated for Best Actor in a Leading Role (Bing Crosby), Best Actress in a Leading Role (Ingrid Bergman), Best Director, Best Film Editing, Best Music, Scoring of a Dramatic or Comedy Picture, Best Music, Song (for Jimmy Van Heusen (music) and Johnny Burke (lyrics) for "Aren't You Glad You're You") and Best Picture.

Bing Crosby's Academy Award nomination for his portrayal of Father Chuck O'Malley made him the first actor in history to receive two nominations for portraying the same character in different films. This was following the previous year's nomination anomaly, where Barry Fitzgerald received nominations in both supporting and lead for the same film (as the same character), the prequel Going My Way. While he lost in lead to his co-star Crosby, Fitzgerald won for Best Supporting Actor.

• The screenplay was adapted into a novel by George Victor Martin.
• There were two radio adaptations of The Bells of St. Mary's on The Screen Guild Theater radio program. Both starred Bing Crosby and Ingrid Bergman. They were broadcast on August 26, 1946 and October 6, 1947.
• A television adaptation on videotape of The Bells of St. Mary's was shown in 1959, starring Claudette Colbert, Marc Connelly, Glenda Farrell, Nancy Marchand, Barbara Myers, Robert Preston, and Charles Ruggles. It was directed by Tom Donovan.

The Bells of St. Mary's has come to be associated with the Christmas season, probably because of the inclusion of a scene involving a Christmas pageant at the school, a major plot point involving an unlikely (yet prayed for) gift, and the film's having been released in December 1945.

In the 1946 film It's a Wonderful Life, in which Henry Travers, a co-star of The Bells of St. Mary's, plays the guardian angel Clarence Odbody, the title of The Bells of St. Mary's appears on the marquee of a movie theater in Bedford Falls, New York. In The Godfather (1972), Michael and Kay see The Bells of St. Mary's at Radio City Music Hall.

• List of Christmas films

• Sarris, Andrew. 1998. “You Ain’t Heard Nothin’ Yet.” The American Talking Film History & Memory, 1927-1949. Oxford University Press. ISBN 0-19-513426-5

• Media related to The Bells of St. Mary's at Wikimedia Commons
• Quotations related to The Bells of St. Mary's at Wikiquote
• The Bells of St. Mary's at IMDb
• The Bells of St. Mary's at AllMovie
• The Bells of St. Mary's at the TCM Movie Database
• The Bells of St. Mary's at the AFI Catalog of Feature Films
• BoxOfficeMojo The Bells of St. Mary's