Sydney Sweeney and Marilyn Monroe Are Ninth Cousins, Genealogy Study Finds

Sydney Sweeney and Marilyn Monroe are ninth cousins, once removed, according to genealogy research that the family-history platform MyHeritage released Wednesday. The company traced the link through the actresses’ fathers. Sweeney’s father, Steven Sweeney, and Monroe’s biological father, Charles Stanley Gifford, both descend from Ezra Perry, a settler in Sandwich, Massachusetts, who lived from about 1625 to 1689. Sweeney’s branch runs through Perry’s son Benjamin, while Monroe’s runs through Deborah Pope. Each line then continues roughly seven more generations to reach the two men.

Roi Mandel, MyHeritage’s director of research, said the researchers began looking after years of public comparisons between the two blondes. Seeing their paths align inspired a search for “a real bond in the MyHeritage archives,” he told Entertainment Weekly. Sweeney has not commented on the finding and did not respond to a request from the magazine.

The connection is distant. At nine generations apart, relatives rarely share measurable DNA, and the result rests on documented family trees, not a genetic test. The match also carries a note of caution: genealogy databases can contain errors, particularly for lineages from the 1600s.

Sweeney has openly courted the Monroe comparison. In February, she wore a vintage Ceil Chapman gown to the Santa Barbara International Film Festival that closely echoed the dress Monroe wore on the 1952 cover of Life magazine. At the December 2025 premiere of “The Housemaid,” she appeared in a white halter gown by Galia Lahav that recalled Monroe’s look in “The Seven Year Itch.” Sweeney has never played Monroe on screen, though several other actresses have taken the part. Monroe died in 1962 at age 36.

MyHeritage has staged similar announcements before. The company previously reported that “Friends” co-stars Matthew Perry and Courteney Cox are distant cousins, and its releases have become a fixture of celebrity news cycles.