1998–2000: ...Baby One More Time and Oops... I Did It Again

1998–2000: ...Baby One More Time and Oops!... I Did It Again

Spears's debut single "...Baby One More Time", released at the end of 1998, became an instant international success; it peaked at number one on the Billboard Hot 100, and sold nine million copies worldwide. The song was also ranked 25th on Rolling Stone and MTV's "100 Greatest Pop Songs of all time". The music video of the song features Spears dressed in a midriff-baring schoolgirl uniform.

The album of the same title was released in January 1999, reaching number one on the Billboard 200. ...Baby One More Time was certified diamond in the U.S. and subsequently achieving worldwide sales of 28 million copies, making it the biggest-selling album by a teenager to date. Spears broke the record in U.S for the youngest artist to have their debut single at number one on the Billboard Hot 100 chart. She also broke the record for the youngest artist to have their debut single and debut album simultaneously at number one on the Billboard charts. Spears still holds this record to date. The album received mixed reviews. Allmusic gave it 4 out of 5 stars, stating that the album "has the same blend of infectious, rap-inflected dance-pop and smooth balladry that propelled the New Kids and Debbie Gibson." While Rolling Stone gave it 2 out of 5, noting that "while several Cherion-crafted kiddie-funk jams serve up beefy hooks, shameless schlock slowies, like 'E-Mail My Heart', are pure spam". The success of Spears's music coupled with her controversial image made her one of the year's biggest stars.