Towards the end of 1998, Spears's debut single "...Baby One More Time" hit the airwaves. Accompanied by a music video that featured the pop princess in a school uniform, the song became an international success, earning double platinum sales and going to number one in the UK, and a large number of countries throughout the world. Her first solo single achieved nine million sales worldwide.[11] The debut album of the same title was released in January 1999,...Baby One More Time reached number one in the Billboard 200.[12] The album received mixed reviews; All Music Guide gave it 4 out of 5 stars, while Rolling Stone gave it 2 out of 5 stars and wrote, "While several Cherion-crafted kiddie-funk jams serve up beefy hooks, shameless schlock slowies, like "E-Mail My Heart," are pure spam."[13][14] The magazine later featured Spears on the April 1999 cover which along with a photo shoot triggered speculation that the still-seventeen-year-old had had breast implants which she denied.[15][16] The success of her music coupled with her controversial image had made her one of the year's biggest stars. Her first album brought her various awards and nominations. In December, she took home four Billboard Music Awards including one for Female Artist of the Year, and the next month won for Favorite Pop/Rock New Artist at the American Music Awards.[17] At the 2000 Grammy Awards Spears received two nominations, including one for Best New Artist which she lost out to Christina Aguilera, and another for Best Female Pop Vocal Performance for "...Baby One More Time."

Following the success of her debut, Spears was ready for her second album. Her second album, Oops!... I Did It Again, debuted at number one in the U.S., where it sold 1,319,193 units during its first week, the record for biggest first-week sales of an album by any female artist.[18] Concerning both musical content and sales, the album was very similar to Spears's debut, although it fared better with critics.[19] The album's lead single, "Oops!... I Did It Again" broke a record for most radio station additions in a single day, and quickly became a U.S. top ten hit and number one single in other countries such as the UK.[20] Spears kicked off her first world tour, the Oops!... I Did It Again World Tour, in the summer of 2000. During a performance at the 2000 MTV Video Music Awards, she ripped off a black suit to reveal a provocative nude-colored and crystal-adorned outfit that generated controversy.[21] She finished the year with two Billboard Music Awards,[22] and received two Grammy nominations for Oops!... I Did It Again in the categories of Best Pop Vocal Album and Best Female Pop Vocal Performance.