Natalie Portman had already started her Hollywood career when she graduated from Harvard with a psychology degree.
And before John Legend was a Grammy Award-winning artist, he worked for a consulting firm.
We rounded up 30 of the smartest celebrities in Hollywood who are high-school valedictorians, Ivy Leaguers, MENSA members, and certified geniuses in their own rights.
Here they are:
Conan O'Brien graduated magna cum laude from Harvard.
Legendary late-night host Conan O'Brien, who was his high school's valedictorian, attended Harvard as a history and literature major. The school newspaper dubbed him the "pre-eminent jokester" of the class of 1985, which makes sense, as he was also the president of the Harvard Lampoon, a semi-secret social organisation that published a humour magazine.
His 72-page senior thesis, "The 'Old Child' in Faulkner and O'Connor," argued that "the New South's emerging identity is manifested in the literature of William Faulkner and Flannery O'Connor via the motif of children that age too quickly."
Allison Williams is more than the smart one on "Girls."
Actress Allison Williams (Getty Images)
Growing up, the "Girls" actress wasn't allowed to act professionally until she graduated from college. She studied English and archaeology at Yale — taking the kind of classes that make you feel like "lying on the ground thinking about things," she said.
When she didn't get a part in Yale's big musical as a freshman, she joined the improv group instead and found she had a knack for comedy.
Cindy Crawford studied chemical engineering on a scholarship at Northwestern University.
Cindy Crawford from the 1994 calendar (Herb Ritts/Pirelli)
Cindy Crawford, who graduated as the valedictorian of her high school class, signed her first modelling contract in 1984. Initially she used the money to supplement her scholarship to attend Northwestern University, but she ditched school to launch her career.
By 1985, she appeared in the pages of Vogue, and would go on to become one of the original Big Six supermodels.
John Legend worked at a prestigious consulting firm.
Before he made it big as a musician, Legend worked at Boston Consulting Group, one of the most prestigious consulting firms in the world.
John Krasinski pursued an array of academic interests at Brown.
Krasinski spent his first semester teaching English in Costa Rica before returning to Brown, where his favorite classes were "Management of Industrial and Nonprofit Organisations" and an introductory biology course.
He later held an internship at "Late Night with Conan O'Brien" before getting cast himself on the big screen.
Natalie Portman has been published twice in scientific journals.
The "Black Swan" lead has a bachelor's degree from Harvard — making her the first alum to win an Academy Award — and took graduate courses at Hebrew University in Jerusalem. She enrolled at Harvard as Natalie Herschlag, her birth name, for the anonymity, but her professors noted that she was an exceptional student.
Portman speaks six languages and has twice been published in scientific journals. As she once told the New York Post, "I'd rather be smart than a movie star."
Matt Damon hatched the idea for "Good Will Hunting" as a Harvard student.
A playwriting class assignment at Harvard led Damon to develop a rough version of "Good Will Hunting." He later completed the project with his childhood friend Ben Affleck, who also stars in the film.
Damon eventually dropped out to pursue acting, but there were no hard feelings: Harvard awarded him the prestigious Harvard Arts Medal in 2013.
In 2015, he played a brilliant scientist in "The Martian."
Lisa Kudrow conducted clinical research on headaches.
Born on 30 July 1963, Lisa Kudrow is the oldest member of the 'Friends' cast (Getty Images)
Kudrow graduated from Vassar College with a degree in biology, and after graduation began working with her father — a world-renowned headache specialist — on a study concerning hemispheric dominance and headache types.
Six months after graduating, Kudrow ditched further education to pursue acting. She became a huge success playing Phoebe on "Friends." She later co-created the critically acclaimed HBO comedy "The Comeback."
Ashton Kutcher hoped to attend MIT or Purdue to study engineering.
But the former "Punk'd" host lost his scholarships and was kicked out of the National Honours Society after breaking into his high school as a prank. He ended up at the University of Iowa, but dropped out at 19 to pursue modelling. Kutcher now divides his time between acting and smart investing in companies like Airbnb, Spotify, and Foursquare.
"The sexiest thing in the entire world is being really smart," Kutcher said during his acceptance speech at the 2013 Teen Choice Awards.
Mayim Bialek plays a neurobiologist on TV and has a Ph.D. in neuroscience in real life.
The lead in NBC's "Blossom" as a kid, Bialek went on to get her bachelor's degree in neuroscience, as well as Hebrew and Jewish studies from UCLA in 2000, though she had also been accepted to Harvard and Yale.
She stepped away from her studies in 2005 to go back to acting and made a huge splash as the über-smart Amy Farrah Fowler on "The Big Bang Theory," but finished her Ph.D. in neuroscience in 2007, specialising in obsessive-compulsive disorder in adolescents with Prader-Willi syndrome.
Edward Norton worked as an analyst for an entrepreneurial nonprofit.
The two-time Oscar nominated actor studied history at Yale, where a back injury forced his early retirement from the crew team. It was then that he tried his hand at theatre.
After graduation, Norton moved to Osaka, Japan, to consult on behalf of his grandfather's nonprofit, Enterprise Foundation, a leading provider of capital and expertise for affordable housing. There he studied Aikido, a martial art, and learned Japanese.
Jake and Maggie Gyllenhaal studied at Columbia University.
When Maggie Gyllenhaal returned to her alma mater to accept a personal achievement award, she said her Columbia education taught her to "acknowledge that I really know nothing." A thirst for knowledge led her, as a first-year English student, to sneak into the dean's senior seminar.
Little brother Jake Gyllenhaal enrolled when Maggie was a senior, and hoped to major in Eastern religions. Following the success of "October Sky," he dropped out after his sophomore year to concentrate on acting.
Kevin Spacey is a Julliard-trained actor.
After graduating at the top of his class in high school, Spacey went on to Julliard to study acting. He dropped out two years later to pursue his career and racked up credits on Broadway before making it big on the silver screen.
A dark-comedy genius, the "House of Cards" star is today an outspoken advocate for the "Netflix model" of television. He has written and spoken at national media conferences about the changing channels of entertainment distribution.
Rashida Jones got her BA in comparative religion from Harvard.
The daughter of Quincy Jones displayed musical and theatrical talents as a student at Harvard, writing music scores and performing in campus plays.
Still, the "Parks and Recreation" actress thought about becoming a lawyer until the OJ Simpson trial made her disillusioned with the justice system. She went on to study religion and philosophy.
David Duchovny attended two Ivy League schools.
The "X-Files" actor graduated with a BA in English literature from Princeton University. He also earned his master's in English lit from Yale University, but abandoned his Ph.D. studies there after booking a beer commercial in '87 led to other auditions.
During his "Inside the Actors Studio" interview, Duchovny revealed that the title of his unfinished doctoral thesis was "Magic and Technology in Contemporary Poetry and Prose."
Kate Beckinsale is fluent in four languages.
Kate Beckinsale has always been an avid reader. Before performing her notable role as Selene in "Underworld," Beckinsale studied French and Russian literature at Oxford University's New College, and still fluently speaks French and Russian, as well as German.
Ken Jeong is a licenced obstetrician.
Best known for his role as Mr. Chow in "The Hangover" and the star of his own sitcom "Dr. Ken," Jeong studied pre-med at Duke University, got his MD at UNC Chapel Hill, then completed his residency in New Orleans.
According to the Washington Post, "he treated patients at an HMO clinic [during the day]; at night, he scooped up as many stand-up gigs as he could." His big break came when Judd Apatow cast him as the OB in "Knocked Up."
Alicia Keys dropped out of Columbia at 16 because of her career.
Alicia Keys performing in Times Square (Getty)
The Grammy-award winning musician began to learn classical piano when she was seven, and shortly enrolled at the Professional Performing Arts School in Manhattan where she began to study jazz. By 14, she was writing her own songs, and at 16, she graduated with all A's.
Four weeks after starting classes at Columbia University, where she had accepted a scholarship, she had to drop out due to her budding music career. She had been signed to Columbia Records when she was 15.
Jordana Brewster was a nerd at Yale.
After the success of "The Fast and the Furious," Brewster left Hollywood to study English at Yale. She was grateful that her burgeoning career hid her identity as the granddaughter of former Yale President Kingman Brewster.
The class of '04 grad said she was a nerd in college. "I was so stressed about getting good grades," she told People. "I wish I had joined a sorority and had more fun."
Eva Longoria has both her bachelor's and master's degrees.
Eva Longoria (Specsavers)
Before she started acting, producing, and launching numerous business ventures, Longoria earned her bachelor's in kinesiology from Texas A&M University—Kingsville.
She later went back to school and graduated with a master's in Chicano studies from California State University, Northridge in 2013. Her thesis was titled: "Success STEMS From Diversity: The Value of Latinas in STEM Careers."
Geena Davis is a member of Mensa.
The Academy-Award winning actress graduated with her bachelor's in drama from Boston University and as a Mensa member, she is considered to have an IQ score "within the upper two percent of the general population."
In 2009, she received an honorary doctorate from Bates College for her work through the Geena Davis Institute on Gender in Media, a non-profit research organisation focused on analysing gender representation in the media industry.
She's currently starring in Fox's "The Exorcist" series, which is slated for a September 2016 premiere.
Nolan Gould graduated high school when he was 13.
The "Modern Family" goof took the GED to graduate high school by the time he was 13 and hoped to take some online college courses. During an interview with Ellen DeGeneres, the teen revealed he has an IQ of 150 and is a Mensa member.
Kara Hayword has been a Mensa member since she was nine.
Hayward was only 12 when she landed her film debut — and breakout role — in Wes Anderson's "Moonrise Kingdom." Now 17, she has been a Mensa member for almost half of her life. She is also a published poet.
This year, she's appearing in "Manchester by the Sea," a drama starring Kyle Chandler, Casey Affleck, and Michelle Williams, and "Paterson," starring Adam Driver.
Elizabeth Banks graduated magna cum laude from UPenn.
Elizabeth Banks made her directorial debut with Pitch Perfect 2 (PA)
Before she was an Emmy-nominated actress and Hollywood star, Banks studied communications and theater arts at the University of Pennsylvania. After graduating magna cum laude, she went on to earn her master's at the American Conservatory Theater.
Kesha had near-perfect SAT scores.
The pop star broke through with her party music, but Kesha was extremely "studious" growing up. She told NPR, "I was in the international baccalaureate program, I loved physics and math, and I was in the marching band. After practice, I would drive to Belmont [a college in Nashville] and listen to Cold War history classes; I just think it's so interesting."
She was going to attend Barnard College to study psychology and comparative religion until her producer, Dr. Luke, convinced her to pursue her music career. The two were embroiled in a legal battle after she sued him for sexual assault, but she dropped the civil lawsuit in August.
Jodie Foster is a French scholar who attended Yale.
Jodie Foster‘s public and private life had a brief meeting at the Golden Globes in 2013 when she publicly referred to her sexuality for the first time (Getty)
Foster could read on her own before she was 3, and juggled a childhood acting career with a heavy course load at Lycée Français de Los Angeles. She later attended Yale to study literature, and went back to acting after graduation.
The critically acclaimed actress has been involved in a variety of roles in film, from acting to directing to producing, and was honored with the Cecil B. Demille honorary Golden Globe in January 2013 for "outstanding contributions to the world of entertainment."
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