In 1953 he appeared in his first Hollywood movie, Elephant Walk (1954), shot in Ceylon and Los Angeles. The circumstances of production were turbulent; filming started with Vivien Leigh in the lead but she had a nervous breakdown during production and had to be replaced by Elizabeth Taylor. The experience helped sour Finch on a Hollywood career and he would only work occasionally there for the rest of his career.
George gained custody of Peter, who was taken from his biological mother and brought up by his adoptive paternal grandmother, Laura Finch (formerly Black) in Vaucresson, France. In 1925 Laura took Peter with her to Adyar, a theosophical community near Madras, India, for a number of months, and the young boy lived for a time in a Buddhist monastery. Undoubtedly, as a result of his childhood contact with Buddhism, Finch always claimed to be a Buddhist. He is reported to have said: "I think a man dying on a cross is a ghastly symbol for a religion. And I think a man sitting under a bo tree and becoming enlightened is a beautiful one."
During his war service Finch was given leave to act in radio, theatre and film. He appeared in a number of propaganda shorts, including Another Threshold (1942), These Stars Are Mine (1943), While There is Still Time (1943) and South West Pacific (1943), the latter for Ken G. Hall. He also appeared in two of the few Australian feature films made during the war, The Rats of Tobruk (1944) and the less distinguished Red Sky at Morning (1944).