According to the California Birth Index, Christina Anstead was born Christina Meursinge Haack in California's Orange County, the setting for Fox's hit teen drama The O.C, on July 9, 1983. The oldest of two, Anstead has a sister, Carly Haack, who is ten years younger than her, but, as Anstead wrote on Instagram, they're "friends for eternity" despite the decade-long age difference.

As a teenager, Anstead attended Canyon High School in Anaheim, and she has kept up with her high school friends since leaving school behind. According to E! News, in 2017, she attended an Anaheim Ducks home game at the Honda Center, where a source said she was joined by "some old friends from high school" during the game. The account noted that Anstead and her old friends "had a great time." Sounds like Anstead formed lifelong friendships as a teen! 

After high school, noted Good Housekeeping, Anstead attended San Diego State University. Upon graduating, she wasted no time jumping into the business world by landing a job in a real estate office. It was there, she detailed in a 2014 promotional video for Flip or Flop, that the then-22-year-old met the man who would be her future husband and TV co-star.