Saint John comes to Netflix from Endeavor, a holding company for talent and media agencies, where she was chief marketing officer. Prior to that she was was chief brand officer at the San Francisco ride-hailing company Uber Technologies (UBER) - Get Report.
She will succeed Jackie Lee-Joe, who joined Netflix in July 2019 from BBC Studios.
"I'm thrilled to join Netflix, especially at a time when storytelling is critical to our global, societal well-being," Saint John said in a statement. "I feel honored to contribute my experience to an already dynamic legacy, and to continue driving engagement."
Saint John, who is 43, "understands how to drive conversations around popular culture better than almost anyone," Netflix's chief content officer, Ted Sarandos, said in a statement.
"As we bring more great stories to our members around the world, she'll define and lead our next exciting phase of creativity and connection with consumers."
Saint John has been vocal about inequality in corporate America and her appointment comes as U.S. companies are looking to diversify their workplaces.
On Tuesday Netflix said it was donating 2% of its cash holdings, an initial investment of up to $100 million, to financial institutions and organizations that "directly support black communities in the U.S."
Lee-Joe is leaving Netflix for personal reasons, Variety reported, as she has been living in Australia with her family since March at the start of the coronavirus pandemic. She joined Netflix in July 2019.
Shares of the Los Gatos, Calif., company at last check were off slightly to $454.