The cause was non-Hodgkin’s lymphoma, his wife, Vashti, said in a statement. Mr. Whitfield, who was from Wales but lived in Australia, was a relatively unknown actor until he was chosen for the series, a sex- and blood-soaked version of the early life of the Thracian gladiator who led a slave rebellion against the Roman ruling class from 73 to 71 B.C.

Mr. Whitfield took what was supposed to be a temporary leave from the show, which was an instant hit after its January 2010 debut, after a routine check-up in March of that year revealed a recurrence of cancer.
Starz Entertainment, the premium channel that airs the show, used different actors to film a prequel called “Spartacus: Gods of the Arena,” while awaiting the star’s return. But Mr. Whitfield never recovered enough to come back.

Liam McIntyre, a virtual unknown from Australia, took over the leading role for the show’s second season.
Mr. McIntyre said then: “Andy’s such a wonderful actor. I don’t want to follow that guy, and everybody hurts that he’s had to give up the role, myself included.”

Chris Albrecht, president and chief executive of Starz, said in a statement, “The man who played a champion on-screen was also a champion in his own life.” Mr. Whitfield faced cancer with “courage, strength and grace,” he said.In addition to his wife, Mr. Whitfield is survived by two children and a sister. In her statement, his wife described him as “our beautiful young warrior.” She said he died in her arms.