"Meta business is strong and well-positioned for the future, so this feels like the right time to step away," Sandberg said in the post, adding that she will serve as an adviser to the company.

Responding to Sandberg, Meta CEO Mark Zuckerberg said he looks forward to "a new chapter together."

Sandberg's decision came after 12 years on the board. She was also the company's chief operating officer for more than 14 years until 2022.

Once second-in-command to founder Zuckerberg, Sandberg was one of the most visible executives at the company and the lead architect of its often-criticized ads-based business model.

Sandberg has been a staunch defender of Facebook over the course of its many controversies, consistently arguing that executives were learning from their mistakes and honing the company's tools to better police against harmful content.

Prior to joining Facebook, Sandberg was vice president of Global Online Sales and Operations at Google and chief of staff for the United States Treasury Department under former President Bill Clinton.

A Harvard University graduate, Sandberg is the author of several books, including the 2013 feminist manifesto "Lean In: Women, Work, and the Will to Lead."