Thomas Adams was born in Corstorphine, near Edinburgh, Scotland on 10 September 1871. After working for a period as a farmer, he moved to London where he was employed as secretary of the Garden City Association. He was also the first manager of Letchworth Garden City from 1903 to 1906. From 1909 to 1914, he worked as Town Planning Adviser to the Local Government Board.
In 1914 he was invited to Canada to work as a town planning adviser to their Local Government Board. During his nearly two decades in Canada his most notable achievements are considered to have been the replanning of Halifax, Nova Scotia, following the cataclysmic explosion in 1917 which destroyed much of the city, and the publication of Rural planning and development : a study of rural conditions and problems in Canada (1917)
While in Canada, he made several visits to the USA where he became a member of the American City Planning Institute and lectured on civic design at Massachusetts Institute of Technology and elsewhere.
In 1922, with Francis Longstreth Thompson (1890-1973), he formed the architectural and town planning plan Adams & Thompson with an office 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.
Adams' involvement in Adams, Thompson & Fry may have been somewhat limited as from 1923 to 1929 he was a director of the Regional Plan of New York, published in 1929, and in 1930 he was appointed part-time director of research in planning by Harvard University in Cambridge, Massachusetts.
In 1930 Adams settled in Battle, East Sussex. Over the next decade he continued to lecture in Britain and the USA. He also produced five important books on urban planning: The Neighborhoods of Small Homes (1931, with Robert Whitten), Recent Advances in Town Planning (1932), The Design of Residential Areas (1934), and The Outline of Town and City Planning (1935).
Adams was elected a Fellow of the Royal Institute of British Architects (FRIBA) in 1934, and was President of the Institute of Landscape Architects from 1937 to 1939. He died at Yew Tree Cottage in Henlys Down, Battle, East Sussex on 24 March 1940.