In 1913, she became the fifth wife of DeWolf Hopper, whose previous wives were named Ella, Ida, Edna and Nella. The similarity in names caused some friction, as he would sometimes call Elda by the name of one of his former wives. Consequently, Elda Hopper paid a numerologist $10 to tell her what name she should use, and the answer was “Hedda”. She began acting in silent movies in 1915. Her motion picture debut was in The Battle of Hearts (1916) with William Farnum, but she made a major splash in Virtuous Wives (1918), in which she established her pattern of playing society women. Hopper decided to upstage the film’s headline starlet, Anita Stewart, by spending all of her $5,000 salary on a lavish wardrobe from the upscale boutique Lucile, which she wore in the film. By 1920, she was commanding $1,000 per week as a free agent in New York; in 1923 she moved to Hollywood and became a contract player for Louis B. Mayer Pictures. She appeared in more than 120 movies over her twenty-three year acting career.

On May 8, 1913, Hopper married actor and singer DeWolf Hopper in New Jersey. They had one child, William, who later played Paul Drake in the Perry Mason series. The couple divorced in 1922.

As Hopper’s movie career waned in the mid-1930s, she looked for other sources of income. In 1935, she agreed to write a weekly Hollywood gossip column for The Washington Herald at $50 a week (equivalent to $932 in 2019), which was cancelled after four months when she refused to take a $15 pay cut.

In 1937, Hopper was offered another gossip column opportunity, this time with the Los Angeles Times. Her column, entitled “Hedda Hopper’s Hollywood”, debuted on February 14, 1938. Hopper could not type, nor spell very well, so she dictated her column to a typist over the phone. Hopper used her extensive contacts forged during her acting days to gather material for her column. Her first major scoop had national implications: in 1939 Hopper printed that President Franklin Roosevelt’s son James Roosevelt was divorcing his wife Betsey after being caught in an affair with a nurse at the Mayo Clinic.

Hopper had an acting role in a radio soap opera, playing Portia Brent on the Blue Network’s Brenthouse beginning in February 1939. She debuted as host of her own radio program, The Hedda Hopper Show, November 6, 1939. Sponsored by Sunkist, she was heard on CBS three times a week for 15 minutes until October 30, 1942. From October 2, 1944, to September 3, 1945, Armour Treet sponsored a once-a-week program. On September 10, 1945, she moved to ABC, still sponsored by Armour, for a weekly program that continued until June 3, 1946. Hopper moved back to CBS beginning on October 5, 1946 with a weekly 15-minute program, This Is Hollywood, sponsored by Procter & Gamble. It ran until June 28, 1947.

Charlie Chaplin was another target of Hedda Hopper’s vitriol because of his alleged Communist sympathies and his relationships with much younger women, which she considered immoral despite her own marriage to a man 27 years her senior. She also objected to him for remaining a British citizen and not becoming an American, which she considered an act of ingratitude towards a country which had given him so much. When in 1943 he denied that he was the father of 22-year old actress Joan Barry’s child, Hopper assisted Barry in filing a paternity suit against Chaplin, launching a campaign of attrition against him through her column and calling for him to be deported for his “moral turpitude”. She defended her behavior by stating that she wished to make an example of Chaplin as “a warning to others involved in dubious relationships.” Her grudge deepened when, later in the year, Chaplin married 18-year old Oona O’Neill and gave the scoop to Louella Parsons out of dislike for Hopper. For years after the paternity trial, Hopper cooperated with the FBI to destabilize Chaplin’s career. This involved her printing damaging information leaked by the FBI concerning Chaplin’s past Communist affiliations, while Hopper in turn provided the agency with unsavory gossip about Chaplin’s personal life gleaned from her informants. Her sustained criticism of Chaplin was one of the factors which contributed to him being denied re-entry to the United States in 1952.

Hopper was one of the driving forces behind the creation of the Hollywood blacklist, using her 35 million strong readership to destroy the careers of those in the entertainment industry whom she suspected of being a Communist, having Communist sympathies, being homosexual, or leading dissolute lives. She was a leading member of the Motion Picture Alliance for the Preservation of American Ideals, founded in 1944 and devoted to rooting out suspected Communists in Hollywood. She considered herself to be a guardian of moral standards in Hollywood and bragged that she need only wag her finger at a producer and he would break off an adulterous affair instantly.

Hopper was an advocate for actress Joan Crawford, whose career suffered in the early 1940s after she was labelled “Box-Office Poison” and forced to resign from Metro-Goldwyn-Mayer. In 1945, Hopper reprinted a press release for Mildred Pierce in her column, which described Crawford as a leading contender for the Best Actress Oscar. Such was Hopper’s influence that she was credited with swinging the decision in Crawford’s favor when she won the award. Hopper’s support has been described as the first instance of lobbying the Academy of Motion Picture Arts and Sciences to favor a certain nominee.

Hopper was a fervent Republican. During the 1944 presidential election, for instance, she spoke before a massive rally organized by David O. Selznick in the Los Angeles Coliseum in support of the Dewey-Bricker ticket as well as Governor Earl Warren of California, who later became Dewey’s running mate in 1948 and later the Chief Justice of the United States. The gathering drew 93,000, with Cecil B. DeMille as the master of ceremonies and Walt Disney as one of the speakers. Others in attendance included Ronald Reagan, Barbara Stanwyck, Ann Sothern, Ginger Rogers, Randolph Scott, Adolphe Menjou, Dick Powell, Gary Cooper, Edward Arnold, and William Bendix. Despite the good turnout at the rally, most Hollywood celebrities who took a public position sided with the Roosevelt-Truman ticket.

Actress Ingrid Bergman was also blacklisted as a result of Hedda Hopper’s sustained negative coverage in her columns. Hopper had supported Bergman in her column throughout the 1940s, advocating for her to land starring roles in The Bells of St. Mary’s (1945) and Joan of Arc (1948). She was enraged when Bergman lied to her about being pregnant with married director Roberto Rossellini’s baby. Hopper had believed Bergman’s denial of the pregnancy, printing a fervent repudiation of the rumor in 1949. However, Bergman was indeed pregnant, and the news was leaked to Hopper’s arch-rival Louella Parsons, who gained the scoop. Seeking revenge, Hopper launched a PR campaign decrying Bergman for being pregnant out of wedlock and carrying a married man’s child.

She was so well known for her conservatism that rumor had it she planned to stand up, unfurl an American flag, and walk out of the 23rd Academy Awards ceremony in March 1951 if Jose Ferrer, who was known to be a socialist, should win Best Actor. The rumor was untrue, but Hopper joked that she wished she had thought of it. Screenwriter Jay Bernstein related that when he told Hopper that many people in Hollywood privately called her a Nazi because of her extreme conservatism, the gossip columnist began to cry and replied: “Jay, all I’ve ever tried to be is a good American.”

In 1958, Hopper made racist remarks to African American actor Sidney Poitier. While interviewing him, she asked if he could sing, because “so many of your people do”. When he replied that he could not, she said: “You’re the first one I’ve ever met who says he can’t sing. I’ve never known any of your people who couldn’t sing.”

On January 10, 1960, a television special, Hedda Hopper’s Hollywood, aired on NBC. Hosted by Hopper, guest interviews included a remarkably eclectic mix of past, current and future stars: Lucille Ball (a longtime friend of Hopper), Francis X. Bushman, Liza Minnelli, John Cassavetes, Robert Cummings, Marion Davies (her last public appearance), Walt Disney, Janet Gaynor, Bob Hope, Hope Lange, Anthony Perkins, Debbie Reynolds, James Stewart, and Gloria Swanson.

In 1963, Hopper complained in her column that three out of five Best Actor Oscar nominees were British and only two were American: “The weather’s so foul on that tight little isle that, to get in out of the rain, they all gather in theatres and practise Hamlet on each other.”

Hopper died on February 1, 1966, of double pneumonia at the age of 80 in Cedars-Sinai Medical Center in Beverly Hills . The probate value of Hopper’s estate was $472,661 gross and $306,679 net. She is buried at Rose Hill Cemetery, Altoona, Pennsylvania.