Bosworth was born in Los Angeles and moved with her parents to San Francisco at age 6, to Connecticut at 9, and to Cohasset, Mass at 14. At this age she began her acting career going on make her mark as an actual teen in a teen drama, starring on The WB's "Young Americans" (2000). Bosworth presented the casting directors for "The Horse Whisperer" with a Christmas card photo in lieu of a professional headshot and landed her first acting role in the 1998 romantic drama (credited as Catherine Bosworth), playing Judith, the ill-fated best friend of the scarred young girl (Scarlet Johansson) who brings together her mother (Kristin Scott Thomas) and the titular hero (Robert Redford).

Following "The Horse Whisperer", Bosworth returned to her non-acting life, attending high school and pursuing various athletic endeavors for eighteen months in an effort to assure that work would not be the main focus of the remaining years of her childhood. In 2000 Kate landed the role of the bratty sister in the upcoming feature film "The Newcomers" and the part of a football co-captain's girlfriend in the upcoming Denzel Washington movie "Remember the Titans". Bosworth more recently starred in the true-life crime drama "Wonderland." Her other film credits include Roger Avary?s "The Rules of Attraction", the independent feature "The Newcomers" and the acclaimed football drama "Remember the Titans", for producer Jerry Bruckheimer. Bosworth also received praise for her work in the television series "Young Americans" for the WB. In 2002, she had a star-making turn in John Stockwell?s "Blue Crush," in which she played the central role of a competitive surfer trying to conquer Hawaii?s daunting Pipeline.

That same year, Kate also appeared in the ensemble cast of writer-director Roger Avary's edgy film adaptation of Brett Easton Ellis' potboiler "The Rules of Attraction," which center on the sexcapades of 1980s-era collegians. After both roles, Bosworth was poised to lay claim to the title of the latest Hollywood "It" girl and her face graced dozens of magazine covers seemingly overnight.

Bosworth is a champion equestrian and plays Varsity soccer and lacrosse. Kate has been accepted to Princeton University, but she has repeatedly deferred her acceptance probably for the sake of movie production. Her eyes are two different colors: Hazel and Blue.