His first film role was as a young and trim Lt. Lothar Zogg, the B-52 bombardier in Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb in 1964. His first big role came with his portrayal of boxer Jack Jefferson in the The Great White Hope a reprise of the role he had performed on Broadway play, which was based on the life of boxer Jack Johnson. For his role, Jones was nominated Best Actor by the Academy of Motion Picture Arts and Sciences, making him the second African-American male performer (following Sidney Poitier) to receive a nomination.
In the early 1970s, James appeared with Diahann Carroll in a film called Claudine, the story of a woman who raises her six children alone after two failed marriages and one "almost" marriage. Ruppert, played by Jones, is a garbage man who has deep problems of his own. The couple somehow overcomes each other's pride and stubbornness and get married.
Jones also played the villain Thulsa Doom in Conan the Barbarian, "Few Clothes" Johnson in John Sayles Matewan, the author Terence Mann in Field of Dreams, the feared neighbor Mr. Mertle in The Sandlot, King Jaffe Joffer in Coming to America, Reverend Stephen Kumalo in Cry, the Beloved Country, Raymond Lee Murdock in A Family Thing, and Vice Admiral James Greer in The Hunt for Red October, Patriot Games, and Clear and Present Danger, among many others.
Jones is also well known as the voice of Darth Vader in the original Star Wars trilogy. Darth Vader was portrayed in costume by David Prowse in the original trilogy, with Jones dubbing Vader's dialogue in postproduction due to Prowse's strong West Country accent being unsuitable for the role.] At his own request, he was originally uncredited for the release of the first two films (he would later be credited for the two in the 1997 re-release):
When Linda Blair did the girl in The Exorcist, they hired Mercedes McCambridge to do the voice of the devil coming out of her. And there was controversy as to whether Mercedes should get credit. I was one who thought no, she was just special effects. So when it came to Darth Vader, I said, no I'm just special effects. But it became so identified that by the third one, I thought, OK I've been denying it, I've been saying it sounds like the uncola nut guy Holder. Geoffrey Holder! ... But for the third one, I said OK, I'll let them put my name on it.
Although uncredited, Jones' voice is briefly heard as Darth Vader at the conclusion of Star Wars Episode III: Revenge of the Sith. When specifically asked whether he had supplied the voice, possibly from a previous recording, Jones told New York Newsday: "You'd have to ask Lucas about that. I don't know." However, on the issue of the voice, the commentary on the DVD release states that, while it will always be uncredited, any true Star Wars fan "should know the answer".
Jones reprised his role as the voice of Vader several times: he is credited in the movie Robots with the voice of Darth Vader from a voice module. Playing the king of Zamunda in the comedy Coming to America, he echoed four Darth Vader phrases. He also vocally appeared as Vader in the comedy film The Benchwarmers and the video games Star Wars: Monopoly and Star Wars: The Interactive Video Board Game. Jones' voice is also used for the Jedi Training Academy attraction at Disneyland and at Disney's Hollywood Studios. Jones returned as Vader for the video game: Lego Star Wars III: The Clone Wars. Jones also reprised his role as Vader in the new Disney attraction; Star Tours: The Adventures Continue and in Star Wars Rebels.