Heigl is the youngest of Paul and Nancy Heigl's five children. At 7, Heigl's 15-year-old brother Jason is thrown from the back of a pickup truck and declared brain-dead. The family decides to donate Jason's organs. "It's one of those things that pretty much devastates an entire family for years and years," Heigl tells New York's Daily News in 2006. "And then it changes the entire dynamic for the rest of your life."
Heigl poses in photos for her aunt's hair care products, and her mother Nancy sends the pictures to talent agencies. The following year, Wilhelmina modeling agency bites, adding Heigl to its roster of talent. She appears in catalogs for Macy's and Sears. "It was fun when I was little but after a while it started to get not as interesting," Heigl tells USA Today in 1994. "There's long hours and all you do is stand around a lot." She goes on to try her hand at acting, appearing in a national TV commercial for Cheerios.
Heigl makes her film debut in the coming-of-age story That Night and appears in Steven Soderbergh's King of the Hill. In 1994, she lands her first leading role in My Father the Hero, playing a precocious teen trying to impress the boy of her dreams. USA Today says, "The scene in which innocent knockout Heigl stands poolside, and sashays off to the beach has everyone – from high school chums to trailer audiences – atwitter."
After shooting the horror sequel Bride of Chucky, Heigl is cast in NBC's adaptation of Shakespeare's The Tempest. "At the time, there was so much going on that I didn't really recognize what a great piece this was," Heigl tells The Gazette. Of Chucky, which opens at No. 2, she says, "The more seriously you try to take something like this, the more ridiculous it seems. Working on it in Toronto, it seemed to get funnier and funnier, as we kept adding things in."
Heigl, 20, makes her TV series debut as Isabel, an orphaned alien disguised as a New Mexico high school student, in the WB cult hit Roswell. Off-screen, Heigl begins dating costar Jason Behr, who plays her brother. After three seasons, Roswell ends in 2002. "The triumph of Roswell is that it takes what sounds like an SNL skit – teen UFO-crash survivors in New Mexico – and plays it straight, with an eerie, noir beauty and stately pacing rare on today's chatty dramas," says a Time review.
Heigl appears in saucy photo spreads, even gracing the cover of Maxim in June. The actress uses her hotness for the teen romance 100 Girls in September with Jaime Pressly, telling Maxim, "It's a cute movie. I just wish I wasn't wearing only jeans and a bra in this one scene?I didn't realize exactly what they do when you're moving around a lot. If they were fake it'd probably look better."
Heigl, 22, stars in the horror film Valentine with Denise Richards. The film focuses on four young women who find themselves terrorized by a Valentine's Day killer. But, Heigl says Valentine will be her last horror flick. "I've sort of had my fill of (the genre)," she tells The Sault Star." In the next few years, she appears in several projects: the thriller Descendant; MTV's modernized update of Emily Bronte's Wuthering Heights; and ABC's telepic prequel Romy and Michele: In the Beginning.
Heigl returns to TV as Dr. Isobel "Izzie" Stevens on the new ABC medical drama Grey's Anatomy with Patrick Dempsey, Ellen Pompeo and Sandra Oh. The mid-season replacement becomes the biggest hospital hit since ER, eventually beating CSI for the No. 1 drama spot. "I've been waiting 15 years for this kind of success," Heigl tells the AP.
In singer Josh Kelley's music video for "Only You," Heigl plays the cute neighbor he romances through their apartment windows. "We were flirting for real through those windows," Heigl tells Cosmopolitan. Adds Kelley to PEOPLE, "At the end of the shoot, I said, 'You're gonna go eat dinner with us, and you can't say no.' So we ate, drank and just started hanging out after that."
Heigl kicks off a busy year of film releases with the pharmaceutical-themed romantic comedy Side Effects. The in-demand actress also stars alongside Jackass star Johnny Knoxville in the Farrelly brothers comedy The Ringer, with Mena Suvari in the indie comedy Caffeine, and with Tom Sizemore in the box office bomb Zyzzyx Road. "The thing about Katie is the girl's a sport," Zyzzyx Road producer and star Leo Grillo tells Entertainment Weekly. "She ran around in a negligee in the desert, and she hated the desert. In one scene of the movie she has to fall, and she did it 10, 11 times."
BIOGRAPHY (top to bottom): Jade Albert; Everett Collection; Everett Collection; RexUSA; ABC; Simon Ferreira/Startraks