Stone's win came after a competitive race in the category, particularly against Lily Gladstone's performance in "Killers of the Flower Moon."
This marks Stone's second Oscar win, following her previous victory in the Best Actress category for "La La Land" in 2017.
"Poor Things" delves into themes of resilience, identity, and the pursuit of happiness, with Stone delivering a nuanced and emotionally powerful performance as the protagonist.
"It's not just about me; it's about a team that came together to create something greater than the sum of its parts," said Stone tearfully upon receiving her award on stage.