Louis Sebastian Theroux (LOO-ee thə-ROO; born 20 May 1970) is a British and American documentarian, journalist, broadcaster, and author. He has received three British Academy Television Awards and a Royal Television Society Television Award.
After graduating from Magdalen College, Oxford, Theroux moved to the United States and worked as a journalist for Metro Silicon Valley and Spy. He moved into television as the presenter of offbeat segments on Michael Moore's TV Nation series.
Theroux is known for his numerous documentaries with the BBC, beginning with Louis Theroux's Weird Weekends (1998–2000), followed by When Louis Met... (2000–2002) and 50 BBC Two specials (2003–present). His work includes studies of unusual and taboo subcultures, crime and the justice system, and celebrities. The majority of his documentaries are set in the United States, but he has also studied cultures in South Africa, Israel, Nigeria, and the UK. The New Yorker described Theroux's work as "a piercingly humane, slyly funny guide through the funkier passages of American culture".