Mayim Chaya Bialik (MY-im bee-AH-lik) (born December 12, 1975) is an American actress, game show host, neuroscientist, and author. She's known for her roles as the title character of the NBC sitcom Blossom, neuroscientist Amy Farrah Fowler on the CBS sitcom The Big Bang Theory, young CC Bloom in Beaches (1988), and the title character in Call Me Kat.

She started her career as a child actress in the late 1980s. Her early roles included the horror film Pumpkinhead (1988) and guest appearances on The Facts of Life and Beauty and the Beast - for which she obtained her Screen Actors Guild (SAG) card. In 1988–89, she had a recurring role on the sitcom Webster as Frieda, Webster's classmate. She appeared in Beaches (1988), playing Bette Midler's character as a young girl. Many contemporary reviews singled out her performance as a strong point in an otherwise emotionally contrived and formulaic film.

She appeared in the music video for Michael Jackson's song "Liberian Girl". In 1990, she was tied to two television pilots, Fox's Molloy and NBC's Blossom. Blossom garnered higher ratings. When Molloy folded after its six episodes, Blossom premiered as a mid-season replacement on January 3, 1991.

She had a major role in the Woody Allen comedy film Don't Drink the Water (1994). Between 1995 and 2005, she mostly did voiceover work for cartoons, including The Real Adventures of Jonny Quest, Disney's Recess and Kim Possible, Cartoon Network's Johnny Bravo, and Nickelodeon's Hey Arnold!.

She had a recurring role on ABC Family's The Secret Life of the American Teenager. In 2009, Clinton Kelly nominated her for a makeover on TLC's What Not To Wear.

She joined the cast of The Big Bang Theory as Dr. Amy Farrah Fowler in 2010 in the season 3 finale as a potential love interest for Sheldon Cooper (Jim Parsons). Before she joined the cast, in the episode "The Bat Jar Conjecture", Raj suggests recruiting the real-life Bialik to their Physics Bowl team, saying "You know who's apparently very smart is the girl who played TV's Blossom. She got a Ph.D. in neuroscience or something." She was one of seven actresses who had a "quirky" personality to audition for the role.

Her character Amy in The Big Bang Theory is a neurobiologist, which is related to Bialik's real-life doctorate in neuroscience. Her performance in The Big Bang Theory earned her Emmy Award nominations in 2012, 2013, 2014, and 2015 for Outstanding Supporting Actress in a Comedy Series. In August 2014, she began hosting a revival of Candid Camera on TV Land along with Peter Funt.

On August 20, 2019, it was announced that she and her new production company, Sad Clown Productions, had signed exclusive contracts with Warner Bros. Entertainment. Her company, in conjunction with Jim Parsons's That's Wonderful Productions, BBC Studios, and Miranda Hart, executive-produces a starring vehicle for Bialik, Call Me Kat, a sitcom based on the British series Miranda; it premiered on Fox on January 3, 2021.

From May 31 to June 11, 2021, she was a guest host of Jeopardy!. On August 11, 2021, it was announced that she would host the series' future primetime specials and spinoffs. On July 27, 2022, it was announced that she and Jennings will be the show's permanent hosts in a job-sharing arrangement.