In 1936, he went to Hollywood to reshoot dialogue for the multinational The Soldier and the Lady (1937) and in the process changed his name from Adolf to Anton. Instead of returning to Austria, Walbrook, who was gay and Classified under the Nuremberg Laws as "half-Jewish" (his mother was Jewish), settled in England and continued working as a film actor, making a speciality of playing continental Europeans.

Producer-director Herbert Wilcox cast him as Prince Albert in Victoria the Great (1937) and Walbrook also appeared in the sequel, Sixty Glorious Years the following year. He was in Director Thorold Dickinson's version of Gaslight (1940), in the role played by Charles Boyer in the later Hollywood remake. In Dangerous Moonlight (1941), a romantic melodrama, he was a Polish Pianist torn over whether to return home. For the Powell and Pressburger team in The Life and Death of Colonel Blimp (1943) he played the role of the dashing, intense "good German" officer Theo Kretschmar-Schuldorff, and the tyrannical impresario Lermontov in The Red Shoes (1948). One of his most unusual films, reuniting him with Dickinson, is The Queen of Spades (1949), a Gothic thriller based on the Alexander Pushkin short story, in which he co-starred with Edith Evans. For Max Ophüls he was the ringmaster in La Ronde (1950) and Ludwig I, King of Bavaria in Lola Montès.

He retired from films at the end of the 1950s and in later years appeared on the European stage and television.

Walbrook died of a heart attack in Garatshausen, Bavaria, Germany in 1967. His ashes were interred in the churchyard of St. John's Church, Hampstead, London, as he had wished in his testament.