90210 looks at life through the eyes of Annie Wilson (Shenae Grimes) and her brother Dixon Wilson (Tristan Wilds), who learn from their first day at West Beverly Hills High School that they're not in Kansas anymore. The Wilson family, including dad Harry Wilson (Rob Estes) and mom Debbie (Lori Loughlin), has relocated to Beverly Hills to keep an eye on Harry's mother Tabitha (Jessica Walter), a feisty-but-faded former television star and a charter member of the Betty Ford Clinic.

For Annie and Dixon, the awkwardness of being the new kids is made worse by the fact that their dad has taken a job as the high school principal. The school is one big culture shock for Annie, a sweet and friendly girl with a passion for the theater, and Dixon, a star athlete and scholar who was adopted by the Wilson family after they took him in as a foster child. Annie and Dixon have a close sibling relationship, which they'll need to help them cope with all the new cliques and classmates, including Naomi Clark (AnnaLynne McCord), a hot, spoiled, rich girl; Ethan (Dustin Milligan), a popular jock whose abilities rival Dixon's; Navid (Michael Steger), an aspiring reporter who heads up the school's daily newscast; and Erin "Silver" Silver (Jessica Stroup), a rebel who produces and stars in a YouTube-type video series.

Even the faculty seems hip and sophisticated at WBHHS, such as smart and funny teacher Ryan Matthews (Ryan Eggold), beautiful guidance counselor Kelly Taylor (Jennie Garth), and successful theater actress turned high school musical director Brenda Walsh (Shannen Doherty). The Wilson family has just begun to realize how much their lives are about to change.