At the official closing of the British Empire Exhibition at Wembley Stadium, Prince Albert, Duke of York, the second son of King George V, addresses the crowd with a strong stammer. His search for treatment has been discouraging, but his wife, Elizabeth, persuades him to see the Australian-born Lionel Logue, a non-medically trained Harley Street speech defects therapist. “Bertie”, as he is called by his family, believes the first session is not going well, but Lionel, who insists that all his patients address him as such, has his potential client recite Hamlet’s “To be, or not to be” soliloquy while hearing classical music played on a pair of headphones. Bertie is frustrated at the experiment but Lionel gives him the acetate recording that he has made of the reading as a souvenir.
After Bertie’s father, King George V, broadcasts his 1934 Royal Christmas Message, he explains to Bertie that the wireless will play a significant part in the role of the royal family, allowing them to enter the homes of the people, and that Bertie’s brother’s neglect of his responsibilities make training in it necessary. The attempt at reading the message himself is a failure, but that night Bertie plays the recording Lionel gave him and is astonished at the lack of stutter there. He therefore returns for daily treatments to overcome the physical and psychological roots of his speaking difficulty.
George V dies in 1936, and his eldest son David ascends the throne as King Edward VIII. A constitutional crisis arises with the new king over a prospective marriage with the twice-divorced American socialite Wallis Simpson. Edward, as head of the Church of England, cannot marry her, even if she receives her second divorce, since both her previous husbands are alive.
At an unscheduled session, Bertie expresses his frustration that, while his speech has improved when speaking to most people, he still stammers when talking to David, at the same time revealing the extent of Edward VIII’s folly with Simpson. When Lionel insists that Bertie himself could make a good king, Bertie accuses Lionel of speaking treason and quits Lionel in anger. Bertie must now face the Accession Council without any assistance.
Bertie and Lionel only come together again after King Edward decides to abdicate in order to marry. Bertie, urged ahead by Prime Minister Stanley Baldwin, ascends the throne as King George VI and visits Lionel’s home with his wife before their coronation, much to the surprise of Mrs. Logue when she comes upon Queen Elizabeth having tea at her dining room table. This is the first time that she learns who her husband’s patient has been.
Bertie and Lionel’s relationship is questioned by the King’s advisors during the preparations for his coronation in Westminster Abbey. The Archbishop of Canterbury, Cosmo Gordon Lang, brings to light that George never asked for advice from his advisors about his treatment and that Lionel has never had formal training. Lionel explains to an outraged Bertie that at the time he started with speech defects there were no formal qualifications and that the only known help that was available for returning Great War shell-shocked Australian soldiers was from personal experience. Bertie remains unconvinced until provoked to protest at Lionel’s disrespect for King Edward’s Chair and the Stone of Scone. Only at this pivotal moment, after realising he has just expressed himself without impediment, is Bertie able to rehearse with Lionel and complete the ceremony.
As the new king, Bertie is in a crisis when he must broadcast Britain’s declaration of war on Nazi Germany in 1939. Lionel is summoned to Buckingham Palace to prepare the king for his address to Britain and the Empire. Knowing the challenge that lies before him, Lang, Winston Churchill, and Prime Minister Neville Chamberlain are present to offer support. The King and Logue are then left in the broadcasting room. He delivers his speech with Logue conducting him, but by the end he is speaking freely. Preparing to leave the room for the congratulations of those present, Logue mentions to the King that he still has difficulty enunciating w and the King jokes back, “I had to throw in a few so they’d know it was me.”
As the Royal Family step onto the palace balcony and are applauded by the crowd, a title card explains that Logue, who received the Royal Victorian Order for service to the Crown, was always present at King George VI’s speeches during the war and that they remained friends until the King’s death from lung cancer in 1952.