Jane Kaczmarek majored in theater at the University of Wisconsin where she met future actor Tony Shalhoub. She later enrolled in Yale University with Shalhoub for her graduate degree and was a part of its theater company. Eventually she has had several Broadway hits, including Lost In Yonkers and Raised In Capativity, where she won an LA Drama Critics Award.

Kaczmarek television work included being series regulars on Equal Justice, Hometown, Big Wave Dave's and The Paper Chase: The Second Year. Her additional credits include recurring roles on Felicity, Party of Five, Frasier, The Practice, Cybill and Hill Street Blues.

She has also appeared in several movies, including the 1998 film Pleasantville, as Tobey Maguire and Reese Witherspoon's mother.

In the year 2000, Kaczmarek was cast to play Lois, in the FOX mid-season replacement Malcolm in the Middle. This proved to be a wise career choice for her, as the show was a hit and made Lois a household name. TV guide dubbed her "true breakout; a female Homer Simpson," and critics hailed her for her comic talents. [1]Later, Kaczmarek would credit the show for bringing out the comedic side of her, claiming "[Before Malcolm] I couldn't even get auditions for comedies. I played very unfunny people." [2]

Kaczmarek is the most decorated cast member on the show, earning 3 Golden Globe Nominations for Best Performance by an Actress In A Television Series - Musical Or Comedy, 1 Screen Actors Guild Awards Nominations for Outstanding Performance by a Female Actor in a Comedy Series, and 6 Emmy Nominations for Outstanding Lead Actress In A Comedy Series (one for every year Malcolm has been on).[3] However, she is still waiting for her first Emmy win.

The show aired its series finale on May 2006. Kaczmarek, however, still guest stars on another FOX Show, The Simpsons, providing the voice of Judge Constance Harm.

Kaczmarek is married to West Wing actor Bradley Whitford and lives in Los Angeles with their three children, Frances (born January 1998), George (December 23, 1999), and Mary (November 25, 2002). Both are very active with charity, and are seen attending many major award shows together. She is the founder of Clothes Off Our Back which auctions celebrity clothing for children's charities. In 2006, Kacmarek and Malcom co-star Erik Per Sullivan contributed the afterward for the children's book Together, that shows the importance of livestock in the world, and was inspired by the mission of the nonprofit charitable organization Heifer International. Jane is 5 feet 9 inches (175 cm) tall.