Budd Schulberg, 95, who created a classic Hollywood heel in the novel What Makes Sammy Run? and later won an Academy Award for the screenplay of On the Waterfront, died yesterday at his home in Westhampton Beach, N.Y., of natural causes, his wife, Betsy, told the Associated Press.

Mr. Schulberg, the son of film industry pioneer B.P. Schulberg, became a best-selling author at 27 with his insider's look at an unscrupulous film executive he called Sammy Glick, a devious back-stabber who claws his way up the studio ladder.

As a youth, Mr. Schulberg had the run of the Paramount Pictures lot, where his father supervised 50 films a year and was head of production from 1925 to 1932. He also went to boxing matches with his father and became a lifelong fan.

Budd Wilson Schulberg was born in New York City on March 27, 1914. Five years later, his father followed the movie industry west to handle publicity for the film magnate Adolph Zukor. Mr. Schulberg mingled with the famous writers and filmmakers who were his father's friends and colleagues.

He graduated in 1931 from Los Angeles High School, where he edited the student newspaper. He then attended Deerfield Academy in Massachusetts for a year before entering Dartmouth College, where he wrote articles for the college paper describing a strike at a marble quarry.

"My crazy luck was that the publisher Bennett Cerf was there lecturing and read my stuff in the paper," Mr. Schulberg told an interviewer in 2005. "He said, 'Young man, this is awfully well written. If you think of writing a novel, come see us.' "

Mr. Schulberg looked up Cerf after a few years in Hollywood. He had soured on a screenwriting career after a bad experience working on the 1937 version of A Star Is Born, and getting fired (along with F. Scott Fitzgerald) from the 1939 movie Winter Carnival. The two had spent a long weekend in an alcoholic fog. He used the incident in his third novel, The Disenchanted, a thinly disguised account of Fitzgerald's decline and their trip together.

Cerf urged Mr. Schulberg to expand a couple of magazine stories based on "Sammy Glick" into a novel, offering a $250 advance. Mr. Schulberg readily accepted. He moved to Vermont and completed What Makes Sammy Run?

The 1941 book changed Mr. Schulberg's life. The bad light it shone on Hollywood also made him and his father virtual outcasts.

More Hollywood scorn arose when Mr. Schulberg willingly testified before the House Committee on Un-American Activities in 1951 about communists in the movie business.

Himself a former Young Communist, Mr. Schulberg never voiced regrets over "naming names." While he didn't approve of the anti-communist witchhunts, he said, "I didn't like the way the party was trying to take over the Screen Writers Guild." In April 2008, a half-century after the controversy, the Writers Guild honored Mr. Schulberg with its lifetime achievement award.

After the war, Mr. Schulberg was completing The Disenchanted when the director Elia Kazan proposed a joint project. The collaboration turned into On the Waterfront. Mr. Schulberg spent months on the docks in Hoboken, N.J., following Pulitzer Prize-winner Malcolm Johnson's pieces about the mob's dominance of longshoremen. Released in 1954, the picture won eight Academy Awards, including best picture, best director, and best screenplay.

Mr. Schulberg worked actively into his 90s, writing in a waterfront home in Quogue, on Long Island. Young filmmakers long sought his advice, and the director Spike Lee worked with him on a project about the heavyweight boxing champion Joe Louis. An early boxing editor at Sports Illustrated, Mr. Schulberg was inducted into the International Boxing Hall of Fame in 2003.

He is survived by his wife; two sons, Benn and Stephen; and two daughters, Jessica and Victoria.