Thomas Duncombe Dee (November 10, 1844 – July 9, 1905) was a Utah businessman. Dee was born in Llanelli, Carmarthenshire, Wales. His parents converted to The Church of Jesus Christ of Latter-day Saints (LDS Church) in 1856, and the family relocated to Ogden, Utah, in 1860. Dee had been working as an apprentice carpenter in Wales, and soon was building residential and commercial buildings in Ogden. In 1876, he joined industrialist David Eccles and in founding businesses in the western U.S. ranging from sugar to lumber to water and shoes and banking.