Francis Longstreth Thompson was born in Croydon, Surrey, England on 3 May 1890 and studied engineering at University College, London. In c.1916, with Ernest Gladstone Allen (1881-1964) he formed the architectural and town planning partnership Allen & Thompson. The pair collaborated in writing The Town Plan and the House: an Opportunity for National Economy (London : The Garden Cities & Town Planning Association, 1917). Homewood House in Cuffley, Hertfordshire, their only known architectural project, is discussed in 'Recent English Domestic Architecture' in Architectural Review April 1917 (pp.80-81).
In 1922, with Thomas Adams (1871-1940) he established the architectural and town planning practice Adams & Thompson in London. The practice was renamed Adams, Thompson & Fry in 1927 when Edwin Maxwell Fry (1899-1987), who had firm since 1925 became a partner. Between the late 1920s and early 1930s Adams, Thompson & Fry produced numerous local and regional town planning reports. The partnership was dissolved in 1934. Thereafter, Thomson appears to have practised alone. He died in Dover, Kent on 19 March 1973