Sarah Drew

Character: Dr April Kepner

In the sixth season of Grey's Anatomy, Sarah Drew was introduced as Dr April Kepner, a resident from Seattle Grace's rival hospital, Mercy West.

Drew starred in Front of the Class and recurred on Private Practice, Privileged and award-winning show Mad Men.

Best known for her series regular work on Everwood, other credits include Weiners, opposite Jenny McCarthy and Andy Milonakis, The Baxter, alongside Elizabeth Banks and Paul Rudd, and Radio, alongside Cuba Gooding and Ed Harris.

Jesse Williams

Character: Dr Jackson Avery

Actor Jesse Williams was introduced to Grey's Anatomy viewers in 2009 and joined the cast as a regular for season seven.

In film, Williams next stars in Cabin in the Woods from producer Joss Whedon. He made his big-screen debut in Sisterhood of the Traveling Pants 2, playing Leo, the love interest to Alexis Bledel. Williams also starred in Brooklyn's Finest from award-winning director Antoine Fuqua, opposite Ethan Hawke, Richard Gere and Don Cheadle.

Past television credits include Greek and Law & Order.

On stage, Williams starred in award-winning playwright Edward Albee's The American Dreambox and The Sandbox at the Cherry Lane Theatre.

He currently divides his time between New York and Los Angeles.

Kim Raver

Character: Dr Teddy Altman

On Grey's Anatomy Kim Raver plays Teddy Altman, an Iraq veteran who has a past with Dr Owen Hunt. Raver last starred as Nico Reilly on Lipstick Jungle from creator Candice Bushnell (Sex In The City).

Raver endeared herself to critics and viewers during the five years she starred as paramedic Kim Zambrano on Third Watch. Following that, she starred for two seasons on the Emmy Award-winning 24 as Audrey Raines. She had a regular role on the children's television series Sesame Street, from the ages of 6 to 9. Other television credits include lead roles on The Nine and Trinity, and guest-starring roles in The Practice, Spin City, Law & Order and a recurring role on Central Park West.

In 2006 Raver appeared in the feature-film Night at the Museum, opposite Ben Stiller and Robin Williams. Other film credits include Prisoner with Julian McMahon, City Hall with Al Pacino, Mind the Gap and Keep Your Distance.

At the start of her career, Raver was discovered by famed director Ridley Scott during a commercial shoot. Her big break came with her Broadway debut in the play Holiday, in which she co-starred with Laura Linney and Tony Goldwyn.

A fine arts graduate of Boston University, Raver continues to study theater in New York with teacher and mentor Wynn Handman. She is fluent in French and German, the latter being a language she learned as a child from her German-born mother.

Sara Ramirez

Character: Callie Torres

Prior to Grey's Anatomy, Sara Ramirez was seen in the Broadway smash-hit Monty Python's Spamolot as Lady of the Lake, for which she earned both a Tony Award for Best Performance by a Featured Actress in a Musical and an Outer Critics Award for Outstanding Featured Actress in a Musical.

Blessed with a rich, smoky voice, Ramirez graduated from the acclaimed Juilliard Drama School. Shortly after graduation, she made her Broadway debut starring as Wahzinak in Paul Simon's The Capeman. She followed that with a starring part in the Gershwins' Fascinating Rhythm, for which she received an Outer Critics Circle nomination for Best Actress.

Her television appearances include NYPD Blue, Law & Order: SVU, Third Watch and Spin City, plus several pilots.

Her concerts have included Martinis at the Martin, Sara Ramirez with Hollis Resnik at The Ravinia, Bravo Bernstein (MTW's 20th Anniversary gala concert) at the Hudson Theatre and The Barrington Stage Company Gala.

Sandra Oh

Character: Cristina Yang

Born and raised in Ottawa, Canada, Sandra Oh started ballet lessons at the age of four and performed in her first play, The Canada Goose, at the age of ten. She started working professionally at age 16 in television, theatre and commercials.

After three years at the prestigious National Theatre School of Canada, Oh beat out more than 1000 other hopefuls and landed the coveted title role in the telefilm, The Diary of Evelyn Lau, based on the true story of a tortured poet who ran away from home and ended up a drug addict and prostitute in Vancouver. Her performance brought her a Gemini (Canada's Emmy) nomination for Best Actress and the 1994 Cannes FIPA d'Or for Best Actress.

Oh won her first Genie (Canada's Oscar) for her leading role in Double Happiness, a bittersweet coming-of-age story about a young Chinese-Canadian woman. She moved to Los Angeles in 1996 to begin the first of six seasons as Rita Wu, the smart and sassy assistant on the comedy series, Arli$$, for which she won a Cable Ace Award for Best Actress in a Comedy. Additional television credits include Six Feet Under and Further Tales of the City. She has been nominated for multiple Emmy Awards and won a Golden Globe Award (Best Actress in a Supporting Role), a Screen Actors Guild Award (Outstanding Performance by a Female Actor in a Drama Series) and a Diversity Award (2005 Creative Liberty Award) for her portrayal of Cristina on Grey's Anatomy.

On the big screen Oh can be seen starring alongside Nicole Kidman and Aaron Eckhart in Rabbit Hole, as the teacher in Ramona and Beezus, as well as The Night Listener, 3 Needles, For Your Consideration, Sideways (for which she received a Screen Actors Guild Award for Outstanding Performance by a Cast in a Motion Picture), Hard Candy and Sorry Haters. Other feature films include Under the Tuscan Sun with Diane Lane, Bean, The Princess Diaries, and Long Life, Happiness and Prosperity.

Chandra Wilson

Character: Dr Miranda Bailey

For her critically-acclaimed role of Dr Miranda Bailey on Grey's Anatomy, Chandra Wilson earned an Actor (Screen Actors Guild Award) for Best Actress in a Drama Series, an Actor for Best Drama Series Ensemble, a Peoples' Choice Award and three NAACP Image Awards. She is also a five-time Emmy nominee and a BET Award nominee.

This Houston, Texas native began performing in musicals at the age of five with Theatre Under the Stars (TUTS), where she appeared in more than ten of their major musical productions. At Houston's Ensemble Theatre she portrayed Li'l Bits in One Monkey Don't Stop No Show and, in the summer of 2005, received their Rising Star honour for her accomplishments. She graduated from Houston's High School for the Performing and Visual Arts, and later went on to acquire her BFA in Drama from NYU's Tisch School of the Arts. There she spent four years training at the Lee Strasberg Theatre Institute.

Wilson's greatest New York stage accomplishment thus far is her portrayal of Bonna Willis in the production of The Good Times are Killing Me, by Lynda Barry, both at the Second Stage and Minetta Lane Theatres, which won her a Theatre World Award for Outstanding Debut Performance. In the Spring of 2004 she was selected by The New York Times as one of "8 to Watch, Onstage and Behind the Scenes." This honour came in conjunction with the Broadway opening of Caroline, or Change, in which she portrayed Dotty Moffett opposite the formidable Tonya Pinkins at the Eugene O'Neill Theatre. She was also in the Broadway productions of Avenue Q and On the Town.

Wilson recently starred in Accidental Friendship for Universal Channel, in which she played a homeless woman who is befriended by a Los Angeles police officer. Other television credits include series regular Claudia Hopper on Bob Patterson, along with numerous guest appearances on The Sopranos, Law & Order, Law & Order: Special Victims Unit, Sex and the City, Third Watch, 100 Centre Street, Cosby and The Cosby Show.

Ellen Pompeo

Character: Meredith Grey

Ellen Pompeo received a Golden Globe nomination for Best Performance by an Actress in a Television Series - Drama at the 2007 Golden Globe Awards. Along with her fellow Grey's Anatomy cast members, she also received the 2007 Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Television Drama.

A Boston native, Pompeo made her major studio film debut in Brad Silberling's Moonlight Mile, alongside Jake Gyllenhaal, Dustin Hoffman and Susan Sarandon. She went on to star opposite Luke Wilson, Vince Vaughn and Will Ferrell in the wildly successful Old School, and in Steven Spielberg's Catch Me If You Can, opposite Leonardo DiCaprio.

Prior to Moonlight Mile, Pompeo had starred in several independent features, including In the Weeds and Coming Soon.