He has performed with the rap group St. Lunatics since 1993 and signed to Universal Records in 1999. Under Universal, Nelly made his solo debut in 2000 with Country Grammar, the title track of which was a top ten hit. The album debuted at #3 on the Billboard 200 and went on to peak at #1. Country Grammar is Nelly's best-selling album to date, selling over 8.4 million copies in the United States. His following album, Nellyville, produced the number-one hits "Hot in Herre" and "Dilemma" featuring Kelly Rowland. Other singles included "Work It" featuring Justin Timberlake, "Air Force Ones" featuring Murphy Lee and the St. Lunatics, "Pimp Juice", and "#1".
With the same-day dual release Sweat and Suit (2004) and the compilation Sweatsuit (2006), Nelly continued to generate many chart-topping hits. Sweat debuted at number two on the US Billboard 200 chart, selling 342,000 copies in its first week. On the same week of release, Suit debuted at number one selling around 396,000 copies in its first week on the same chart. Nelly's fifth studio album, Brass Knuckles, was released on September 16, 2008 after several delays. It produced the singles "Party People", featuring Fergie, "Stepped on My J'z" and "Body On Me", featuring Akon and Ashanti.
In 2010, Nelly released the album 5.0. The lead single, "Just a Dream", has appeared in the top ten of several singles charts and were certified platinum in the United States. The second single is "Move That Body" featuring T-Pain and Akon. "Gone" is the sequel to Nelly's 2002 worldwide number one single "Dilemma", also with Rowland, and serves as third single from Nelly's album.
He won Grammy Awards in 2003 and 2004 and had a supporting role in the 2005 remake film The Longest Yard with Adam Sandler and Chris Rock. He has two clothing lines, Vokal and Apple Bottoms. He has been referred to by Peter Shapiro as "one of the biggest stars of the new millennium", and the RIAA ranks Nelly as one of the best-selling male artists in American music history, with 21 million albums sold in the United States.On December 11, 2009, Billboard ranked Nelly the #3 Top Artist of the Decade.