The childhood and adolescence that Shearer once described as “a pleasant dream” ended in 1918, when her father’s company collapsed, and her older sister, Athole, suffered her first serious mental breakdown. Forced to move into a small, dreary house in a “modest” Montreal suburb, the sudden plunge into poverty only strengthened Shearer’s determined attitude: “At an early age, I formed a philosophy about failure. Perhaps an endeavor, like my father’s business, could fail, but that didn’t mean Father had failed.”

In January 1920, the three Shearer women arrived in New York, each of them dressed up for the occasion. “I had my hair in little curls”, Shearer remembered, “and I felt very ambitious and proud.” Her heart sank, however, when she saw their rented apartment: “There was one double bed, a cot with no mattress and a stove with one gas jet. The communal bathroom was at the end of a long, dimly lit hallway. Athole and I took turns sleeping with mother in the bed, but sleep was impossible anyway—the elevated trains rattled right past our window every few minutes.”

Finally, a year after her arrival in New York, she received a break in film: fourth billing in a B-movie titled The Stealers (1921). In January 1923, Shearer received an offer from Louis B. Mayer Pictures, a studio in Northeast Los Angeles that was run by a small-time producer, Louis B. Mayer. Irving Thalberg had moved to Louis B. Mayer Pictures as vice president on February 15, 1923, but had already sent a telegram to Shearer’s agent, inviting her to come to the studio. After three years of hardship, she found herself signing a contract. It called for $250 a week for six months, with options for renewal and a test for a leading role in a major film called The Wanters.

The apprenticeship served Shearer well. On April 26, 1924, Louis B. Mayer Pictures was merged with Metro Pictures and the Samuel Goldwyn Company to form Metro-Goldwyn-Mayer. Shearer was cast with Lon Chaney and John Gilbert in the studio’s first official production, He Who Gets Slapped. The film was a conspicuous success and contributed to the meteoric rise of the new company, and to Shearer’s visibility. By late 1925, she was carrying her own films, and was one of MGM’s biggest attractions, a bona fide star. She signed a new contract; it paid $1,000 a week and would rise to $5,000 over the next five years. She bought a house for herself and Edith at 2004 Vine Street, which was located under the Hollywoodland sign.

At the end of a working day in July 1925, Shearer received a phone call from Thalberg’s secretary, asking if she would like to accompany Thalberg to the premiere of Chaplin’s The Gold Rush. That night, they made their first appearance as a couple. A few weeks later, Shearer went to Montreal to visit her father. While there, she had a reunion with an old school friend, who remembered: “At the end of lunch, over coffee, Norma leant in across the table. ‘I’m madly in love’, she whispered. ‘Who with?’ I asked. ‘With Irving Thalberg’, she replied, smiling. I asked how Thalberg felt. ‘I hope to marry him’, Norma said, and then, with the flash of the assurance I remembered so well, ‘I believe I will.'”

Over the next two years, both Shearer and Irving saw other people. Louise Brooks remembered: “I held a dinner party sometime in 1926. All the place cards at the dinner table were books. In front of Thalberg’s place was Dreiser’s Genius, and in front of Norma’s place, I put The Difficulty of Getting Married. It was so funny because Irving walked right in and saw Genius, and sat right down, but Norma kept walking around. She wouldn’t sit down in front of The Difficulty of Getting Married – no way!”

By 1927, Shearer had made a total of 13 silent films for MGM. Each had been produced for under $200,000, and had, without fail, been a substantial box-office hit, often making a $200,000+ profit for the studio. She was rewarded for this consistent success by being cast in Ernst Lubitsch’s The Student Prince in Old Heidelberg, her first prestige production, with a budget over $1,000,000. While she was finishing The Student Prince, Shearer received a call summoning her to Thalberg’s office. She entered to find Thalberg sitting at his desk before a tray of diamond engagement rings. He granted her the option to choose her own ring; she picked out the biggest. After weeks of rumors, provoked by wearing the ring, it was announced in August 1927 that they were to wed. On September 29, 1927, they were married in the Hollywood wedding of the year. Shearer had two children with Thalberg – Irving Thalberg, Jr. (1930–1987), and Katherine (1935–2006). Before they were married, Shearer converted to Judaism so she could marry Thalberg.

Shearer was nominated for an Academy Award for Best Actress on six occasions, winning only for The Divorcee in 1930. She was nominated the same year for Their Own Desire, for A Free Soul in 1931, The Barretts of Wimpole Street in 1934, Romeo and Juliet in 1936, and Marie Antoinette in 1938. Marion Davies later recalled that Shearer came to a party at San Simeon in her Marie Antoinette costume; Davies said she was not about to remove the door so Shearer could enter, so Norma made her grand entrance through wider doors leading from another room. Four chairs were arranged so she could sit at the table in her voluminous skirts.

The enforcement of the Production Code in 1934 forced Shearer to drop her celebrated “free soul” image, and move exclusively into period dramas and “prestige” pictures. Of these, The Barretts of Wimpole Street (1934) proved her most successful at the box office, making a profit of $668,000, in part because the film contained elements that slipped by the newly instituted Production Code. In that film, she played a role made famous by Katharine Cornell. Shearer also took on another play popularized by Cornell in Romeo and Juliet (1936) (her first film of the 1930s to lose money), and Marie Antoinette (1938) (a budget of almost $2,500,000 was too great for the studio to expect a profit), though their elaborate sets and costumes helped make the films immensely popular with audiences.

After Thalberg’s unexpected death on September 14, 1936, Shearer retained a lawyer to ensure that Thalberg’s percentages of films on which he had worked were still paid to his estate, which was contested by MGM. When she took the story to gossip columnist Louella Parsons, the studio was forced to give in and granted all the profits from MGM movies made and released from 1924 to 1938, meaning the estate eventually received over $1.5 million in percentage payments. Nevertheless, Shearer’s contract was renewed for six films at $150,000 each. During this time, she embarked on a brief romance with the younger actor James Stewart, and then with the married actor George Raft. Raft (who had separated from his wife years earlier, soon after they married) stated publicly that he wanted to marry Shearer. However, his wife’s refusal to allow a divorce and the disapproval of MGM studio head Louis B. Mayer caused Shearer to end the affair.

In 1939, she attempted an unusual role in the dark comedy Idiot’s Delight, adapted from the 1936 Robert E. Sherwood play. It was the last of Shearer’s three films with Clark Gable, after A Free Soul (1931) and Strange Interlude (1932). The Women (1939) followed, with an entirely female cast of more than 130 speaking roles.

Critics praised the suspenseful atmosphere in her next film, Escape (1940), where she played the lover of a Nazi general who helps an American free his mother from a concentration camp. With increasing interest in the war in Europe, the film performed well at the box office, but Shearer passed up roles in highly successful films Now, Voyager and Mrs. Miniver, to star in We Were Dancing and Her Cardboard Lover (1942), which both failed at the box office. In 1942, Shearer unofficially retired from acting.

Following her retirement in 1942, she married Martin Arrougé (March 23, 1914 – August 8, 1999), a former ski instructor 11 years her junior. Despite often attending public events in her later life, Shearer gradually withdrew from the Hollywood social scene. In 1960, her secretary stated: “Miss Shearer does not want any publicity. She doesn’t talk to anyone. But I can tell you that she has refused many requests to appear in motion pictures and TV shows.” Arrougé and Shearer remained married until her death.

Shearer’s fame declined after her retirement in 1942. She was rediscovered in the late 1950s, when her films were sold to television, and in the 1970s, when her films enjoyed theatrical revivals. By the time of her death in 1983, she was best known for her “noble” roles in Marie Antoinette and The Women.

On June 12, 1983, Shearer died of bronchial pneumonia at the Motion Picture Country Home in Woodland Hills, California, where she had been living since 1980.

A Shearer revival began in 1988, when Turner Network Television began broadcasting the entire Metro-Goldwyn-Mayer film library. In 1994, Turner Classic Movies began showcasing her films, most of which had not been seen since the reconstitution of the Production Code in 1934. Shearer’s work was seen anew, and the critical focus shifted from her “noble” roles to her pre-Code roles.

On June 30, 2008, Canada Post issued a postage stamp in its “Canadians in Hollywood” series to honour Norma Shearer, along with others for Raymond Burr, Marie Dressler, and Chief Dan George.

Most of Shearer’s MGM films are broadcast on Turner Classic Movies, and many of them are also available on DVD from Warner Home Video. In 2008, she was inducted into Canada’s Walk of Fame. In 2015, a number of Shearer films became available in high-definition format, authored by Warner Home Video, in most cases, from the nitrate camera negatives: A Free Soul, Romeo and Juliet, Marie Antoinette, and The Women.