The son of a well-known wood carver, John Steell, Gourlay was an extremely successful animal painter. Born in Edinburgh, he began his artistic studies under the guidance of his father, before continuing under William Allan at the school of the Board of Manufactures and then in the studio of Robert Scott Lauder. A regular exhibitor at the Royal Scottish Academy, Gourlay was elected an Associate in 1846 and an Academician in 1859. Fourteen years later, he was appointed animal painter to Queen Victoria for Scotland following the death of Sir Edwin Landseer. He quickly became the most popular painter of animals and sporting subjects in Scotland at this time. In 1882 he was appointed curator of the National Gallery of Scotland.