Bland was the son of John Bland and Susanna de Deblere Bland. He was born probably in London, where he was christened on January 6, 1630, in the parish of Saint Antholin, Budge Row. His father died in April 1632, after which his elder brother John Bland assumed direction of the family’s extensive commercial interests. As a young man Theodorick Bland resided for several years in Sanlúcar de Barrameda, Spain, where the family engaged in the wine trade. In the mid-1640s he succeeded his brother Edward Bland as the family’s agent in the Canary Islands, and following Edward Bland’s death by May 1652, Bland moved to Virginia to take control of the large landed property that the family owned there. His name first appears in Virginia records as foreman of a Surry County jury on November 3, 1653.