Child actor Dickie Moore with Marlene Dietrich in "Blonde Venus," 1932.

Before he was Dick Moore, public relations executive for arts groups and labor unions, he was known to millions of moviegoers as Dickie Moore, blond-haired, big-brown-eyed child actor in more than 100 films.

His debut came at 11 months, when he portrayed John Barrymore’s character as an infant in the 1927 silent movie “The Beloved Rogue.” He later was Marlene Dietrich’s son in “Blonde Venus” (1932), played the title role in “Oliver Twist” (1933) and appeared in a series of “Our Gang” shorts.

He literally grew up before the cameras, planting the first screen kiss on Shirley Temple for the movie “Miss Annie Rooney” (1942). It was also his own first buss, onscreen or off, and he recalled being “traumatized” by the experience.

Mr. Moore was 89 when he died Sept. 7 at a hospice center near his home in Wilton, Conn. He had dementia, said Helaine Feldman, president of Dick Moore & Associates.

For a period, Mr. Moore was one of Hollywood’s most prolific young actors, playing a child cured of rabies by Paul Muni in “The Story of Louis Pasteur” (1936) and the son of the persecuted French military officer Alfred Dreyfus in “The Life of Emile Zola” (1937).

Dick Moore, former child actor, in 1984. (Harry Naltchayan/The Washington Post)

He made 19 films in 1932 alone and received thousands of fan letters. Signing them became so rote that the young star once quipped that, at 8, he accidentally signed his mother’s birthday card, “from your friend, Dickie Moore.”

Film critics found him appealing, but over time he admittedly did not develop the range — and the consistent star billing — that made enduring household names of onetime child stars such as Temple, Mickey Rooney, Elizabeth Taylor, Margaret O’Brien, Natalie Wood or Roddy McDowall.

Nevertheless, he shared the screen with some of the biggest names of his era, including W.C. Fields (“Million Dollar Legs,” 1932), Barbara Stanwyck (“So Big!,” 1932) and Spencer Tracy (“Man’s Castle,” 1933). His favorite role was the younger brother of World War I hero Alvin York in “Sergeant York” (1941), starring Gary Cooper.

Mr. Moore’s film career waned in adolescence, but he avoided some of the hardships suffered by many of his peers: the fortunes squandered by avaricious parents and guardians, the descent into alcoholism or drug abuse or other wayward behavior, the lack of even a high school education to forge the path to new opportunities.

Mr. Moore once described his parents as “very penurious people from poor hard-scrabble stock” who rewarded him with a dime after completing every film. They tried to give him an ordinary childhood, without the usual Hollywood indulgences. He went to public school, not a cloistered classroom on a studio lot.

He served in the Army during World War II and became a correspondent in the Pacific for the Stars and Stripes newspaper. That enabled him to use the G.I. Bill to attend some college classes.

“I had learned how to do something — I could edit a magazine, work on a newspaper,” he told The Washington Post in 1984. “I wouldn’t have known if I hadn’t gone to college. Those who had the most trouble were those who didn’t have money saved for them and those who were never encouraged to do anything else.”

John Richard Moore Jr. was born Sept. 12, 1925, in Los Angeles. He entered movies through a family friend who worked as a secretary for a studio executive.

After his return from military duty, he found his fortunes in Hollywood had changed. Where he had once had carte blanche at a studio, he now had to wait at the front gates for a chaperon. Where directors had once clamored for him, he was forced to audition. He began an intensive period of psychoanalysis.

There were intermittent screen roles. He was the young deaf and mute friend of Robert Mitchum in one of the finest of all film-noir dramas, “Out of the Past” (1947), and his final movie role was as a soldier in “The Member of the Wedding” (1952), based on the book and play by Carson McCullers.

Mr. Moore also narrated, co-produced and co-directed an Oscar-nominated short film, “Boy and the Eagle” (1949). He did some stage acting, then became public relations director for the Actors’ Equity Association, the stage actors union, and was editor of its magazine. He started his own firm in 1966.

He wrote a book, “Twinkle, Twinkle, Little Star: But Don’t Have Sex or Take the Car” (1984), for which he interviewed dozens of former child actors. “All of us shared common lives and times, huge responsibilities and salaries that shriveled fathers’ egos,” he wrote.

Amid his research, he fell in love with the former child actress and movie musical star Jane Powell. They wed in 1988.

His earlier marriages to Patricia Dempsey and Eleanor Fitzpatrick ended in divorce. Besides his wife, survivors include a son from his first marriage, Kevin Moore; three stepdaughters; a sister; and several grandchildren.

Mr. Moore once told The Post that when he saw his old movies or photos, he felt little connection to that part of himself. He also expressed no interest in the child actors of the present.

“I’m impatient,” he said. “I don’t empathize with them at all, they’re just too cute and adorable for words. Doesn’t it make you sick to your stomach?”