Christine Jane Baranski (born May 2, 1952) is an American stage and screen actress, and is known for her Emmy Award-winning portrayal as Maryanne Thorpe in the sitcom Cybill, Dr. Beverly Hofstadter (Leonard Hofstadter's mother) in The Big Bang Theory and her Emmy-nominated portrayal of Diane Lockhart in The Good Wife. Prior to her appearances in film and television, Baranski rose to prominence as a Broadway actress, winning two Tony Awards, and has continued to work in the theatre alongside her screen appearances.