Douglas Alexander Smith (born June 22, 1985) is a Canadian-American actor most notable for his work on the HBO series, Big Love as Ben Henrickson, the eldest son of polygamist Bill Henrickson. He portrayed Tyson in the film adaption of The Sea of Monsters.
Smith was born in Toronto, Ontario, Canada, the son of Terrea (née Oster), an American teacher, and Maurice Smith, a British-born, Vancouver-based producer of low-budget films. Smith's mother appeared in several of the films that his father produced during the 1980s. He is the younger brother of actor Gregory Smith.
As a teenager, he went to Australia to play the lead role as an American boy living in Australia in a series called Out There. In addition to being a series regular on Big Love, Smith has also co-starred in the films Sleepover, Rock the Paint, Santa's Slay, and State's Evidence.