In New Zealand, the Recording Industry Association of New Zealand (RIANZ) compiles the top forty singles chart each week. Sales of songs determined 75% of the sorting information, and radio airplay figures were responsible for 25%.^[1] From 18 April 2004 to 29 May 2007 the sales/radio airplay split was 50:50.^[1][2] Downloads of songs were included from 29 May 2007.^[3] The reporting period is from Monday to Sunday, with the week's chart published the next Monday.^[4] Before 18 April 2004, the chart week was from Sunday to Saturday, with the chart published on Sunday.^[5] Afterwards, the chart week was from Monday to Sunday, with the charts published on Monday. This meant there was a one-day charting period for 18 April 2004, with the next chart published on 19 April 2004. As a result, Usher spent three weeks and one day at number one with "Yeah!" instead of four complete weeks.

A total of 170 singles topped the chart in the 2000s, including 23 by New Zealand artists. Twenty artists had three or more number-one singles; the most successful was Akon, whose seven number-ones totalled twenty-three weeks on top of the chart. Chris Brown, Eminem, and the Black Eyed Peas each had five of their singles go to number one.

Scribe's double A-side "Stand Up"/"Not Many" spent the longest at number one, with twelve weeks. This is the most weeks at number one ever by a New Zealander, and the second most for any song, after Boney M.'s "Rivers of Babylon" had fourteen weeks in the top spot in 1978.^[6] "Axel F", by Crazy Frog, and "Brother", by Smashproof and Gin Wigmore each had eleven weeks at the top spot. "Brother" broke the record for the longest consecutive number-one reign by a New Zealand artist, previously set by "Sailing Away" by All of Us in 1986.^[7]

On 29 May 2006, "Crazy" by Gnarls Barkley replaced "Hips Don't Lie" by Shakira and Wyclef Jean at the top of the chart, and became the 500th number-one single in the RIANZ New Zealand Singles Chart's history.^[6]

The source for this decade is the Recorded Music NZ chart, the chart history of which can be found on the Recorded Music NZ website or Charts.nz.^[8][9]

 *  – Number-one single of the year^{[nb 1]}

 †  – Song of New Zealand origin^{[nb 2]}

 ‡  – Number-one single of the year, of New Zealand origin

2000

2001

2002