Thomas Meehan (21 March 1826 Potters Bar, which was in Middlesex at the time and is now in Hertfordshire, England – 19 November 1901), was a noted British-born nurseryman, botanist and author.

Meehan travelled to Philadelphia in 1848 and worked first for Robert Buist at his Rosedale Nursery, then between 1850 and 1852 for the owner of Bartram's Garden, who was pioneer locomotive builder Andrew M. Eastwick (1811–1879) and who, with Thomas De Kay and Joseph Harrison Jr., had contracted to build the first railroad in Russia.

In 1854 Meehan started a nursery firm in partnership with William Saunders in Germantown near Philadelphia, where he lived with his family for the rest of his life.

Meehan and family supplied plants to the United States and Europe for seven decades, expanding to cover 60 hectares in the twentieth century.

Meehan wrote his own agriculture columns for five newspapers and also authored 'The Native Flowers and Ferns of the United States', consisting of four volumes describing and illustrating, in colour, over 300 species.

John Bartram (1699–1777), the well-known early American botanist, explorer, and plant collector, founded the garden in September 1728 when he purchased a 102-acre (0.41 km2) farm in Kingsessing Township, Philadelphia County.

In 1850, financial difficulties led to the historic garden's sale outside of the 122 year ownership by the family to Andrew M. Eastwick (1811–1879), who preserved it as a private park for his estate.

Despite the disappearance of a number of subsidiary physical elements in the landscape, the garden's rectilinear framework designed and laid out by Bartram during the second quarter of the eighteenth century is still recognizable.

Thanks to efforts of Meehan and Charles S. Sargent, Bartram's House and Garden's physical endurance demonstrates eighteenth- and nineteenth-century botanic studies, the North American plant and seed business, and period domestic life in Philadelphia.