Knox was born in Paisley, the son of a yarn merchant. In 1817 his name appears as a teacher of drawing at 40 Dunlop Street in Glasgow. Four years later the title 'Landscape Painter' was added to this entry in the Glasgow Street Directory and we know that Daniel MacNee, Horatio McCulloch and William Leighton Leach came to this studio as pupils. Between 1828 and 1836 Knox lived in London and exhibited works at the Royal Academy and British Institute. He returned to Glasgow in 1836, but moved to Keswick in 1840, dying there in January 1845. Knox is known for his panoramic landscapes. He travelled around the west coast of Scotland as shown by a collection of lithographs Scottish Scenery drawn upon Stone by John Knox which was published in 1823. Knox was possibly influenced by William Daniell's A Voyage round Great Britain (1813-25). He was an important influence in the development of art in Glasgow, both as a teacher and as a painter.