Sebastian Stan (born August 13, 1982) is a Romanian American actor, known for his role as James "Bucky" Barnes / Winter Soldier in Captain America: The First Avenger and Captain America: The Winter Soldier. He played The Mad Hatter/Jefferson on the ABC's fantasy drama Once Upon a Time, Prince Jack Benjamin on Kings and Carter Baizen on Gossip Girl. He also appeared in Black Swan. In 2012, he appeared in the USA Network miniseries Political Animals starring alongside Sigourney Weaver.
His role in Political Animals earned him a nomination at the Critics' Choice Television Award for Best Performance by a Supporting Actor in a Miniseries.
Stan was born in Constanța, Romania. At age 8, he and his mother moved to Vienna, where she was employed as a pianist. Four years later (at age 12), he moved with his mother to Rockland County, New York after she married an American, the headmaster of a private academy.
During Stan's years at the Rockland Country Day School, he starred in productions such as Harvey, Cyrano de Bergerac, Little Shop of Horrors, Over Here!, and West Side Story. He also attended the Stagedoor Manor summer camp where he was introduced to acting and was cast in many camp productions. It was then that he decided to take acting seriously and began to apply for acting programs at several universities. He was accepted to and attended Rutgers University's Mason Gross School of the Arts. This gave him the opportunity to spend a year abroad studying acting at Shakespeare's Globe Theatre in London, England.
In 2010, he appeared in Darren Aronofsky's ballet thriller, Black Swan. Stan also began filming the supernatural horror film The Apparition in February of that year; the film was released on August 24, 2012.
Stan played Blaine, the main antagonist of Hot Tub Time Machine in March 2010. Later that same year, he played Bucky Barnes in the film Captain America: The First Avenger, based on the Marvel Comics character. Stan reprised the role in the 2014 sequel, Captain America: The Winter Soldier.
In 2012, he starred in the thriller Gone and began a recurring role on Once Upon a Time as the Mad Hatter. The A.V. Club described his work in "Hat Trick", his premiere episode, as "excellent" and placed the episode in their list of the 30 best episodes of 2012 from series which did not make their top list. He also appeared in the USA Network miniseries Political Animals as the troubled gay son of the former first lady.
In 2013, Stan played the role of Hal Carter in the Roundabout Theater Company's production of William Inge's Picnic, at the American Airlines Theater in New York.
Stan was in a relationship with his Gossip Girl co-star Leighton Meester for about two years, from 2008 to 2010. He dated Dianna Agron from May to December of 2011. He also dated Once Upon a Time co-star Jennifer Morrison from February 2012 to August 2013.
|2004||Tony n' Tina's Wedding||Johnny|
|2006||The Architect||Martin Waters|
|2006||The Covenant||Chase Collins|
|2007||The Education of Charlie Banks||Leo|
|2008||Rachel Getting Married||Walter|
|2010||Hot Tub Time Machine||Blaine|
|2011||Captain America: The First Avenger||James Buchanan "Bucky" Barnes|
|2014||Captain America: The Winter Soldier||Bucky Barnes / Winter Soldier|
|2003||Law & Order||Justin Capshaw||Episode: "Sheltered"|
|2007–2010||Gossip Girl||Carter Baizen||11 episodes|
|2009||Kings||Jonathan "Jack" Benjamin||Main cast; 12 episodes|
|2012||Once Upon a Time||The Mad Hatter/Jefferson||6 episodes|
|2012||Political Animals||Thomas "T.J." Hammond||Miniseries|
|2011||Captain America: Super Soldier||James "Bucky" Barnes||Voice|
|2008||"Wake Up Call"||Hayden Panettiere|
Source : http://en.wikipedia.org/