Lucas York Black was born on November 29, 1982 in Decatur, Alabama to Jan (Keenum), an office worker, and Larry Black, a museum worker. With no formal acting lessons, Lucas made his film debut with a small part in the Kevin Costner film The War (1994) at age 11. This small role helped him land his next job in the series American Gothic (1995). When the series went to North Carolina to cast its primary roles, the casting people in Wilmington remembered Lucas, and suggested him for the role of "Caleb Temple." Although the series didn't last long, Lucas's film career did. He was next seen in the sleeper hit Sling Blade (1996), then in another dark film, Ghosts of Mississippi (1996).

A bit of Calvin Klein modeling and mainly school and sports occupied the rest of his spare time. He scored another summer hit with The X Files (1998) and finally got a lead role in the independent film Crazy in Alabama (1999). Selective about his film roles, Lucas turned down an opportunity to star in the movie adaptation of The Horse Whisperer (1998) due to the request of having his accent altered. In 2000 he was seen with Matt Damon in All the Pretty Horses (2000).

Lucas graduated from Speake High School in 2001; he had been a good student and also played football, basketball, and a little bit of golf. An avid bass fisherman, he plans to study fish biology. After a small break, he will next be seen alongside Hollywood stars Jude Law and Natalie Portman in the drama Cold Mountain (2003).