Sarah Louise Christine Chalke (/ˈtʃɔːk/; born August 27, 1976) is a Canadian actress. She is known for her starring roles as the second Becky Conner in the ABC sitcom Roseanne (1993–1997), Elliot Reid in the NBC/ABC medical comedy series Scrubs (2001–2010), Beth Smith and Space Beth in the Adult Swim animated science fiction series Rick and Morty (2013–present), and Kate Mularkey in the Netflix drama series Firefly Lane (2021–2023).

Chalke had recurring roles as Stella Zinman in the CBS sitcom How I Met Your Mother (2008–2009, 2014) and as Angie in the ABC/TBS sitcom Cougar Town (2012). She also had voice roles in the Netflix animated sitcom Paradise PD (2018–2021) and the Netflix animated adventure series Dogs in Space (2021–2022).

Chalke was born at the Ottawa Civic Hospital on August 27, 1976, in Ottawa, Ontario, and was raised in North Vancouver, British Columbia. She is the middle of three daughters born to Douglas and Angela Chalke (née Piper).

She is from a German family who spoke German at home, and went to a school where she spoke French all day, so she speaks both languages fluently.

Chalke graduated from Handsworth Secondary School in North Vancouver in 1994.

Chalke's acting career began at age eight when she began appearing in musical theatre productions. At 12, she became a reporter on the Canadian children's show KidZone. In 1993, she took over the role of Rebecca Conner on Roseanne after Lecy Goranson left the series; Chalke made a cameo appearance as a different character in the Roseanne episode "Halloween: The Final Chapter" (#178, originally aired October 31, 1995) after Goranson returned. Chalke later returned to the role of Becky after Goranson departed for a second time. After the show ended, Chalke returned briefly to Canada, where she starred in the CBC Television drama Nothing Too Good for a Cowboy (1998–1999). In 1999, she also starred as a Russian KGB agent in the film Y2K (also known as Terminal Countdown), alongside Louis Gossett Jr. and Malcolm McDowell.

In 2001, she was cast as Dr. Elliot Reid in the NBC comedy series Scrubs and she would be a cast member for all nine seasons until the series ended its run in 2010. She has appeared in several feature films, including Ernest Goes to School and Cake. She appeared in Channel 101's The 'Bu with The Lonely Island, a parody of the hit show The O.C., but was credited as "Pamela Fenton". In 2007, she appeared as a supporting character in Chaos Theory, which starred fellow Canadian Ryan Reynolds. In 2008, Chalke became the spokesperson for a line of women's underwear by Hanes that included a series of commercials directed by her Scrubs co-star Zach Braff. In 2008 and 2009, she made appearances in the CBS sitcom How I Met Your Mother as Stella Zinman. In early 2011, she starred in the CBS television series Mad Love, a romantic comedy which debuted as a midseason replacement and was cancelled after only one season was produced.

Chalke was signed by former Scrubs executive producer Bill Lawrence to play the love interest of Bobby Cobb in the series Cougar Town. She appeared in multiple episodes in the third season. Chalke starred in the ABC comedy series How to Live with Your Parents (For the Rest of Your Life), which premiered April 3, 2013, and which was cancelled one month later. She played Polly, a single and very uptight divorced mother who found herself moving back in with her parents (Elizabeth Perkins and Brad Garrett) because of the economic downturn. Also in 2013, she played a frantic mother named Casey Hedges in the Grey's Anatomy season 9 episode "Can't Fight This Feeling". Chalke also voices Beth Smith and Space Beth on the Adult Swim animated science-fiction series Rick and Morty.