Thomas Hayton Mawson (5 May 1861 – 14 November 1933), known as T. H. Mawson, was a British garden designer, landscape architect, and town planner.
Mawson was born in Nether Wyresdale, Lancashire, and left school at age 12. His father, who died in 1877, was a warper in a cotton mill and later started a building business. He married Anna Prentice in 1884 and the Mawsons made their family home in Windermere, Westmorland, in 1885. They had four sons and five daughters. His eldest son, Edward Prentice Mawson, was a successful landscape architect and took over the running of his father's firm when his father developed Parkinson's disease in 1923. Another son, John Mawson, moved to New Zealand in 1928 as Director of Town Planning for that country.
Mawson died at Applegarth, Hest Bank, near Lancaster, Lancashire, aged 72, and is buried in Bowness Cemetery within a few miles of some of his best gardens and overlooking Windermere.
To make a living, he worked first in the building trade in Lancaster, then at a London nursery where he gained experience in landscape gardening. In the 1880s he moved back north, where he and two brothers started the Lakeland Nursery in Windermere. The firm became sufficiently successful for him to be able to turn his attention to garden design.
Mawson's first commission was a local property, Graythwaite Hall, and his work there showed his hallmark blend of architecture and planting. He went on to design other gardens in Cumbria such as Langdale Chase, Holehird, Brockhole, and Holker Hall around the turn of the century.