John Stewart was born in Auchterarder, Perthshire, Scotland in 1869 [or 1870 - sources differ]. He was articled to Andrew Heiton (1823-1894) in Perth from 1886 to 1890 during which time he attended Edinburgh School of Art. He then worked as an assistant to John Burnet (1814-1901), John James Burnet (1857-1938) and John Archibald Campbell (1859-1909) from 1890 to 1892; to Robert Rowand Anderson (1834-1921) of Wardrop & Anderson from 1892 to 1897; and to John James Burnet of John Burnet & Son in 1899-1901.
Stewart commenced independent practice as an architect in Glasgow in 1900 and in 1901 formed a partnership with George Andrew Paterson (1876-1934) as Stewart & Paterson. Stewart continued the practice following the death of Paterson in 1934.
Stewart was an Owen Jones Student in 1899. He was elected a Licentiate of the Royal Institute of British Architects (LRIBA) in 1911 and a Fellow of the Royal Institute of British Architects in 1931. He died on 17 March 1954.
For a chronological list of architectural projects by John Stewart see Dictionary of Scottish Architects 1660-1980