Hopper died at his home in Venice, Calif., where he had lived for many years, the Los Angeles Times reported. He was 74.
He announced in October last year that he had been diagnosed with prostate cancer, the Times said.
The son of a postal worker, Hopper grew up in San Diego. He got his first big break at the age of 19 when he played a gang member in "Rebel Without A Cause," the 1955 James Dean picture.
By the time he made "Easy Rider," Hopper had already had an up-and-down career, a pattern that continued. While the low-budget "Easy Rider" became a huge hit, his next movie, "The Last Movie," flopped.
Hopper spent more than a decade doing little work and a lot of drugs until he was admitted to a Los Angeles psychiatric ward in 1984. He then decided to channel his energy into work, becoming what critic Roger Ebert called the "most dependable and certainly the creepiest villain in the movies."
Hopper separated from his fifth wife in January. He had four children.
While Hopper was identified with the 1960s counter-culture, he was politically conservative. But in 2008 he supported Barack Obama for president, telling an ABC interviewer on election day he rejected the Republicans because of their choice of Sarah Palin for vice president.