Mary-Kate Olsen (born June 13, 1986) is an American actress, producer, author and fashion designer. She made her career debut in 1987 alongside her twin sister Ashley Olsen in the television series Full House. Following the huge success of Full House in America, Mary-Kate and Ashley established a successful career starring in television and film roles that saw her become an international household name.Founded in 1993, the production company Dualstar was created to produce and merchandise films and TV shows starring Mary-Kate and Ashley, becoming an extremely profitable enterprise.Mary-Kate became joint CEO of Dualstar in 2004, securing her position in the Forbes celebrity rich list. Mary-Kate is the older sister of Elizabeth Olsen.

Twin sister of Ashley Olsen.
When she was young, she and Ashley used to call their “Full House” (1987) co-stars by their characters’ names so they wouldn’t mess them up during taping.
Older sister of Elizabeth Olsen. Younger sister of Trent Olsen.
In real life she and Ashley are very close to John Stamos, who played their uncle Jesse on “Full House” (1987).
Enjoys shopping, going to the movies, listening to rock music (ie., Counting Crows), cheer-leading and Tae Bo with her sister.
Has two horses, CD and Star, and has won several prizes with them.
She and Ashley both had to wear fake teeth during the later years of “Full House” (1987) because their teeth began to look different.
At age 6, she and Ashley became the youngest producers in history.
Has a bi-monthly magazine called Mary-Kate and Ashley Magazine
Has a line of clothing with sister Ashley that is sold at Wal-Mart
Enjoys yoga and horseback riding.

In 1993 she and Ashley were supposed to play young Eves (Teena and Cindy) on “The X Files” (1993), but were eventually replaced by the Krievins twins (Erika Krievins and Sabrina Krievins) from the nearby of Vancouver. The reason were very strict child labor laws.
Ranked #61 in FHM’s ’100 Sexiest Women’ poll of 2003
On their 17th birthday (June 13, 2003), the US’s Cable News Network (CNN) announced not only their birthday but the twins’ total financial worth – $150,000,000 for each. The same news source predicted the twins may be billionaires by the time they’re 21.
During the earlier seasons of “Full House” (1987), the producers did not want it known that Michelle was played by twins, so Mary-Kate and Ashley were credited as Mary Kate Ashley Olsen.
She and her sister became the youngest self-made millionaires in American history before they were 10 years old.
Has a cousin named Christine
Her favorite subjects in school are English and creative writing
Voted the 20th most wanted young star for the new year by “Access Hollywood” (1996) and The-N networks. Her twin sister Ashley wasn’t part of the honor.
Her favorite band is Dave Matthews
Wears a size 6.5 shoe.
She is younger than Ashley by about 2 minutes
She has reportedly entered a program for treatment of an eating disorder. [June 22, 2004]
Her favorite movie from 1986 is Labyrinth (1986).
Her favorite party song is Rock Your Body.
At 17, she and her twin sister Ashley were rated 2003′s 2nd hottest teen female stars.
She and Ashley both missed their high school prom to host “Saturday Night Live” (1975). The cast made it up to them by giving them a fake prom when they did their monologue.
She donated many signed head-shots to Rocky Stone to be auctioned off to raise money to buy more toys for less fortunate kids as part of the Toy Mountain Campaign 2004.
Born at 10:28 am PDT.
Ranked #3 in VH1′s list of the “100 Greatest Kid Stars” with sister Ashley
Parents are David & Jarnette (divorced)
Has a half-sister, Taylor & a half-brother, Jake.
Likes small specialty shops in Soho, South Beach, and Los Angeles.
Majors in Cuisine at New York University.
Named #32 in FHM’s “100 Sexiest Women in the World 2005″ special supplement. (2005)
Her film New York Minute (2004/I) earned only $5.96 million during its opening weekend. This was the lowest amount ever earned for any film opening in over 3,000 theaters.
During the filming of “Full House” (1987), she acted out the comedic scenes while Ashley took on the more serious ones.
While making the film To Grandmother’s House We Go (1992) (TV) in Canada, she rode her first horse and becomes a devoted equestrian.
She and her sister Ashley were both ranked #6 in E’s 50 cutest child stars all grown-up.(2005)
Mentioned in the song High School Never Ends by Bowling for Soup.
Is very close to her older cousin Christine.
Hospitalized November 19, 2007 in New York for a kidney infection.
Was ranked #5 on Forbes List of The 20 Top-Earning Young Superstars.(2007). with sister Ashley.
In 2004, her wealth was estimated at $137 million.
Close friend of Heath Ledger.
She is of Danish and Norwegian descent.
In May 2000, she and her sister, Ashley Olsen, dedicated the Holland-America Line cruise ship, the “MS Zaandam”.
With her sister, Ashley Olsen, went to school with Briana Evigan.
Broke up with boyfriend Nate Lowman [February 24, 2010].
Mary-Kate is shorter than her twin sister Ashley by 1 inch.