Christina Applegate was born in Hollywood, California, to Robert William 'Bob' Applegate, a record producer, and Nancy Lee Priddy, a singer and actress. Growing up in a show business family significantly influenced her early exposure to the entertainment industry.

Applegate made her television debut at just a few months old in a Playtex commercial alongside her mother, Nancy Priddy. This marked her earliest foray into the world of acting.

Throughout the early 1980s, Applegate appeared in various television shows, including 'Quincy, M.E.,' 'Charles in Charge,' 'Silver Spoons,' and 'All Is Forgiven.' These guest roles helped build her experience and visibility within the industry.

Applegate landed a recurring role as Robin Kennedy in the short-lived NBC sitcom 'Heart of the City.' Although the series was not a long-term success, it provided her with more substantial on-screen time and further honed her acting skills.

At age 15, Applegate was cast as Kelly Bundy, the ditzy and promiscuous daughter in the Fox sitcom 'Married… with Children.' This role catapulted her to fame and defined a significant portion of her early career. The show ran for 11 seasons and became a cultural phenomenon.