In 1805 Reinagle was elected an associate of the Society of Painters in Watercolours, and in 1806 a member. He became its treasurer in 1807, and was president from 1808 to 1812 Between 1806 and 1812 he sent to its exhibitions sixty-seven drawings, mostly Italian landscapes and scenery of the English lakes. During the same period he exhibited portraits and landscapes in oil at the Royal Academy, of which he became an associate in 1814, and an academician in 1823. He was a clever copyist of the old masters, and is said to have been much employed by a picture-dealer in restoring and "improving" their works.