Beatty was born on May 30, 1869 and went to school in Toronto, Ontario. He was a member of the volunteers who served in the North-West Rebellion in 1885, then worked in the Toronto Fire Department (1869–1900). In his leisure time, he studied art with George Agnew Reid and other teachers. In 1900, he studied at the Académie Julian in Paris with Jean-Paul Laurens and Benjamin Constant. He travelled throughout Europe from 1906 to 1909, painted at the Académie Julian and Colarossi, and travelled to London where he attended the London Chelsea Polytechnic. He made trips to Holland, Belgium and other places to sketch and worked up the sketches when he returned home into many dark, rich, moody paintings of Dutch peasant life and other subjects. From 1912 to 1941, he worked at the Ontario College of Art. Over time, his work changed to more vibrant tones.