He studied at the Slade School of Art 1902-1906 with Henry Tonks and under Jean-Paul Laurens at the Académie Julian in Paris, 1906-1908, and held his first solo exhibition at the Goupil Gallery in 1914.
He served in the Middlesex and Royal Berkshire Regiments (1914-1919) during the First World War. Strang also produced some artworks during the War and the British War Memorials Committee purchased one large painting and several drawings of French battlefields from him. Strang exhibited at the Royal Academy from 1923 and the New English Art Club from 1919.
He also visited and studied in Italy, Belgium, Spain and Sicily.
Among his paintings was a notable portrait of James Dickson Innes. In 1944 Strang submitted five drawings of bomb damaged buildings in central London to the War Artists" Advisory Committee, WAAC, and the Committee purchased four of them.
WAAC purchased a further two drawings of similar subjects in July 1945 for thirty guineas. Strang was married to Frances and had a brother David (1887-1967) who was also an artist.
Ian Strang died at Wavendon, Buckinghamshire, on 23 March 1952.
A memorial exhibition was held at the Leicester Galleries in 1952.
He was elected an Associate member of the Royal Society of Painter-Etchers and Engravers in 1925 and became a full member in 1930.