The Wilson family arrives in Beverly Hills, after Harrison "Harry" Wilson takes a job as the principal at West Beverly High School, while his children, Annie and Dixon, attend the school during their first week much to the awkward circumstances of their father watching over them, while Harry and his photographer wife, Debbie, also keep a close eye on Harry's washed-up, alcoholic, actress mother, Tabitha. For Annie and Dixon, 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, a hot and stereotypical spoiled rich girl who believes that money buys everything; Ethan Ward, Annie's former boyfriend from Kansas who's now Naomi's boyfriend, and a popular lacrosse star whose abilities rival Dixon's; Navid Shirazi, an aspiring student reporter who heads up the school's daily TV newscast; and Erin Silver, a rebel and wanna-be socialite who produces and stars in a YouTube-type video series, and who develops a crush on Dixon. Adrianna is a fellow student and theater "goddess" who is Naomi Clark's best friend... and Ethan Ward's secret girlfriend, and who has a serious drug addiction; George Evans is an arrogant West Beverly High student, who takes an instant dislike to Dixon because of his race (Dixon is black). Wendy is "sexy vixen" student at West Beverly Hills High who takes every advantage of her looks; Ty Collins is another student and theater major. Even the faculty seems hip and sophisticated at the school whom include the smart and funny teacher Ryan Matthews, beautiful guidance counselor Kelly Taylor, and successful theater actress-turned-high school-musical director Brenda Walsh. The Wilson family has just begun to realize how much their lives are about to change.

Naomi finds herself in trouble when she fails an assignment, and Ryan and Kelly bring the issue to Harry's attention, while Harry struggles with a disturbing revelation about the result of a secret tryst with Naomi's mother, Tracy, from many years ago. Meanwhile, Dixon learns more about Navid when they team up to try to pull a school prank against Palisades High. Annie meets a potential love interest in the form of drama student Ty Collins, who turns out to be the wealthiest student at West Beverly, and who spirits her away for San Francisco for the evening. Silver posts the story about Ethan's infidelity with Naomi on her Internet blog, while Adrianna continues her self-destructive slide into drugs and debauchery. Also, Ryan tries to ask Kelly out on a date, but she has to find a babysitter first for her four-year-old son, and former West Beverly alumni Brenda Walsh, now a successful Broadway and London theater director, arrives back in town to help put on a new school play.

Harry and Debbie welcome Sean into their home, while Dixon, Annie, and Tabatha welcome him awkwardly despite the fact that they don't know much about him, while Naomi and her mother, Tracy, welcome him to their home as well. Meanwhile, Kelly and Brenda's friendship is slowly fading away and gets wider after Brenda is hospitalized from an accident and confides in Kelly that she seduced Ryan weeks earlier. Naomi decides to hang out with a new group of girls at school despite Ozzie's advice that they want nothing to do with her. Also, Silver feels threatened when a cheerleader, named Christina, shows too much interest in Dixon who shares the same interests he does.

Adrianna reveals the secret that she's pregnant individually to both Naomi and Navid, who handle the news differently than expected. When Dixon reveals the depths of his feelings to Silver, their relationship takes a surprising turn when she reveals some facts about herself and that of her feelings of love. Meanwhile, Tabitha surprises Annie and Dixon with an unexpected belated Christmas gift of a car: which both Debbie and Harry disapprove of Tabitha trying to buy her grandchildren's affection after she also announces that she is leaving town to re-start her acting career with a job on a TV soap opera in New York. With a massive heat wave hitting the L.A. area, Annie and Ethan decide to to take a day-long escape to Tabitha's house Palm Springs for a romantic time alone.

Donna finds herself in a dilemma when she confides in Kelly during a night on the town that she must decide between returning to Japan and being with David, or moving back to Beverly Hills and keeping their 20-month-old daughter, Ruby, which leads her to decide to open up her own design shop in Los Angeles. Meanwhile, Silver is the topic of gossip at West Beverly due to her recent mental issues and does not know if she is ready to return to school. While Annie and Naomi try to patch things up between them in order to help Silver, Annie soon overhears that Naomi's father is being served a sexual harassment lawsuit, and she keeps it to herself... and later regrets it when Naomi is evicted from her hotel suite. Ethan continues on his downward spiral due to Liam's bad influence in wanting to be a bad guy as Liam is. Also, Adrianna and Navid meet with potential adoptive parents for the baby. Elsewhere, Harry and Debbie hold a yard sale when they finally sell their Kansas house and try to get rid of all of their old house's possessions as they plan to move out of Tabitha's house and to find a house of their own in Beverly Hills.

Following their engagement, Navid and Adrianna celebrate their respective bachelor and bachelorette parties. While Adrianna feasts with Annie, Naomi, Silver, and their female friends at the Wilson home, Liam takes Navid, Ethan, and Dixon to have a wild night on the town with some college girls at a burlesque club. Meanwhile, sparks fly between Ryan and Jen, and Dixon continues to feel unappreciated by Silver. Jen also persuades Naomi to stand up to their father as well as move in with her at a local house, while Naomi continues to grow more insecure as well as jealous over Liam when she sees him talking with Annie whom he sees as naive and holding back her own dark side.