A portrait painter in the neo-Romantic style, Gerald Mackenzie Leet was educated at Goldsmiths College, The Royal College of Art and the Courtauld Institute. He was given his first teaching appointment at Ealing School of Art. He spent the Second World War mainly in South Africa and Egypt, when Lord Wavell, Viceroy of India came across his work and organized his appointment in 1945 as an official war artist, based in New Delhi. After the war, Leet became assistant drawing master at Eton until, towards the end of the forties, he began teaching part-time at Brighton College of Art.
Leet painted many portraits of famous people, including aristocracy and royalty; in 1948 he was commissioned to paint the Queen (Elizabeth Bowes-Lyon, the late Queen Mother) and members of her staff at Windsor Castle. and exhibited at, amongst other galleries the Eton Art Gallery, the Isobar Gallery in Hampstead and the Halifax and Manchester City Art Galleries. He was a noted collector of paintings and particularly of rare books, and well-known too for the idiosyncratic and entertaining figure he cut in his social circle. His long but often troubled friendship with Denton Welch, who had been an art student at the same time as Leet, was incorporated into several of Welch’s books, and Leet painted a portrait of Welch (1935).