Sir William MacTaggart FRSE RSA (1903–1981) was a Scottish painter known for his landscapes of East Lothian, France, Norway and elsewhere. He is sometimes called William MacTaggart the Younger to distinguish him from his grandfather, the painter William McTaggart.
William MacTaggart was born at Loanhead in Midlothian. He went to Edinburgh College of Art between 1918 and 1921, and there he made friends with other young artists like William Gillies, Anne Redpath, John Maxwell, William Crozier and Adam Bruce Thomson. Later they would be considered the core group of the Edinburgh School. Crozier was a major artistic influence on MacTaggart, and he joined his friend on some of his trips to the south of France, made for the sake of MacTaggart's health, as well as for painting opportunities.
In 1927 he joined the Society of Eight whose members included Cadell and Peploe, and two years later held his first solo exhibition. In the early 1930s he shared a studio with Gillies. Around the same time he met Fanny Aavatsmark, a Norwegian, and they married in 1937.
MacTaggart started teaching at Edinburgh College of Art in 1933 and was president of the Society of Scottish Artists between 1933 and 1936. In 1948 the Royal Scottish Academy made him an Academician and he later served as president from 1959 to 1964. He was also a member of the Royal Academy in London and was knighted in 1962.