Stone appeared in three films released in 2009.
The first of these was opposite Matthew McConaughey, Jennifer Garner and Michael Douglas in Mark Waters' Ghosts of Girlfriends Past.
Loosely based on Charles Dickens' 1843 novella A Christmas Carol, the romantic comedy has her playing a ghost who haunts her former boyfriend.
Critical reaction to the film was negative, though it was a modest commercial success.
Her most financially profitable venture that year was Ruben Fleischer's $102.3 million-grossing horror comedy film Zombieland, in which she features alongside Jesse Eisenberg, Woody Harrelson and Abigail Breslin.
In the film, she appeared as a con artist and survivor of a zombie apocalypse, in a role which Empire's Chris Hewitt found to be "somewhat underwritten."
In a more positive review, The Daily Telegraph's critic wrote, "[T]he hugely promising Stone ... [is] a tough cookie who projects the aura of being wiser than her years."
Stone's third release in 2009 was Kieran and Michelle Mulroney's Paper Man, a comedy-drama which disappointed critics.

Stone provided the voice of an Australian Shepherd in Marmaduke (2010), a comedy from director Tom Dey, which is based on Brad Anderson's long-running comic strip of the same name.
Her breakthrough came the same year with a starring role in Easy A, a teen comedy directed by Will Gluck.
Partially based on Nathaniel Hawthorne's 1850 historical romance novel The Scarlet Letter, the film tells the story of Olive Penderghast (Stone), a high school student who becomes embroiled in a comic sex scandal after a false rumor circulates that she is sexually promiscuous.
Stone read the script before the project was optioned for production, and pursued it with her manager while production details were being finalized.
She found the script "so different and unique from anything I'd read before", saying that it was "funny and sweet".
When Stone discovered that the film had begun production, she met with Gluck, expressing her enthusiasm for the project.
A few months later, the audition process started and she met again with Gluck, becoming one of the first actresses to audition.
The film received positive critical reviews, and Stone's performance was considered its prime asset.
Anna Smith of Time Out commented: "Stone gives a terrific performance, her knowing drawl implying intellect and indifference with underlying warmth."
With a total box office of $75 million, the film was a commercial success.
Stone was nominated for a BAFTA Rising Star Award and a Golden Globe Award for Best Actress in a Musical or Comedy, and won the MTV Movie Award for Best Comedic Performance.

In October 2010, Stone hosted an episode of NBC's late-night sketch comedy Saturday Night Live; her appearances included a sketch playing off her resemblance to Lindsay Lohan.
Stone described it as "the greatest week of my life".
She hosted it again in 2011, appeared in an episode in 2014, and in its 40th anniversary special in 2015.
A brief appearance in the sex comedy Friends with Benefits (2011) reunited her with Gluck.
She followed this with a supporting role in Glenn Ficarra and John Requa's romantic comedy Crazy, Stupid, Love (2011) alongside Steve Carell, Ryan Gosling and Julianne Moore.
The film features her as a law school graduate, and the love interest of Gosling's character.
Despite finding "some inevitable collapses into convention" in the film, Drew McWeeny of HitFix wrote that Stone "ties the whole film together".
At the 2012 Teen Choice Awards, she won the Choice Movie Actress – Comedy award for her performance in the film.
Crazy, Stupid, Love was a box office success, grossing $142.9 million worldwide with a production budget of $50 million.

Disillusioned at being typecast as the "sarcastic interest of the guy", Stone co-starred with Viola Davis in Tate Taylor's period drama The Help (2011), a film she found challenging.
The film is based on Kathryn Stockett's 2009 novel of the same name and is set in 1960s Jackson, Mississippi.
She met with Taylor to express a desire to work in the film.
Taylor has said: "Em
Stone appeared in three films released in 2009. The first of these was opposite Matthew McConaughey, Jennifer Garner and Michael Douglas in Mark Waters' Ghosts of Girlfriends Past. Loosely based on Charles Dickens' 1843 novella A Christmas Carol, the romantic comedy has her playing a ghost who haunts her former boyfriend. Critical reaction to the film was negative, though it was a modest commercial success. Her most financially profitable venture that year was Ruben Fleischer's $102.3 million-grossing horror comedy film Zombieland, in which she features alongside Jesse Eisenberg, Woody Harrelson and Abigail Breslin. In the film, she appeared as a con artist and survivor of a zombie apocalypse, in a role which Empire's Chris Hewitt found to be "somewhat underwritten." In a more positive review, The Daily Telegraph's critic wrote, "[T]he hugely promising Stone ... [is] a tough cookie who projects the aura of being wiser than her years." Stone's third release in 2009 was Kieran and Michelle Mulroney's Paper Man, a comedy-drama which disappointed critics.
Stone provided the voice of an Australian Shepherd in Marmaduke (2010), a comedy from director Tom Dey, which is based on Brad Anderson's long-running comic strip of the same name. Her breakthrough came the same year with a starring role in Easy A, a teen comedy directed by Will Gluck. Partially based on Nathaniel Hawthorne's 1850 historical romance novel The Scarlet Letter, the film tells the story of Olive Penderghast (Stone), a high school student who becomes embroiled in a comic sex scandal after a false rumor circulates that she is sexually promiscuous. Stone read the script before the project was optioned for production, and pursued it with her manager while production details were being finalized. She found the script "so different and unique from anything I'd read before", saying that it was "funny and sweet". When Stone discovered that the film had begun production, she met with Gluck, expressing her enthusiasm for the project. A few months later, the audition process started and she met again with Gluck, becoming one of the first actresses to audition. The film received positive critical reviews, and Stone's performance was considered its prime asset. Anna Smith of Time Out commented: "Stone gives a terrific performance, her knowing drawl implying intellect and indifference with underlying warmth." With a total box office of $75 million, the film was a commercial success. Stone was nominated for a BAFTA Rising Star Award and a Golden Globe Award for Best Actress in a Musical or Comedy, and won the MTV Movie Award for Best Comedic Performance.
In October 2010, Stone hosted an episode of NBC's late-night sketch comedy Saturday Night Live; her appearances included a sketch playing off her resemblance to Lindsay Lohan. Stone described it as "the greatest week of my life". She hosted it again in 2011, appeared in an episode in 2014, and in its 40th anniversary special in 2015. A brief appearance in the sex comedy Friends with Benefits (2011) reunited her with Gluck. She followed this with a supporting role in Glenn Ficarra and John Requa's romantic comedy Crazy, Stupid, Love (2011) alongside Steve Carell, Ryan Gosling and Julianne Moore. The film features her as a law school graduate, and the love interest of Gosling's character. Despite finding "some inevitable collapses into convention" in the film, Drew McWeeny of HitFix wrote that Stone "ties the whole film together". At the 2012 Teen Choice Awards, she won the Choice Movie Actress – Comedy award for her performance in the film. Crazy, Stupid, Love was a box office success, grossing $142.9 million worldwide with a production budget of $50 million.
Disillusioned at being typecast as the "sarcastic interest of the guy", Stone co-starred with Viola Davis in Tate Taylor's period drama The Help (2011), a film she found challenging. The film is based on Kathryn Stockett's 2009 novel of the same name and is set in 1960s Jackson, Mississippi. She met with Taylor to express a desire to work in the film. Taylor has said: "Em
Emma Stone