Adult Contemporary is a chart published by Billboard ranking the top-performing songs in the United States in the adult contemporary music (AC) market. In 2001, eight different songs topped the chart in 52 issues of the magazine, based on weekly airplay data from radio stations compiled by Nielsen Broadcast Data Systems.
In the year's first issue of Billboard, the number one song was "The Christmas Shoes" by the contemporary Christian music group NewSong, which moved into the top spot that week. The song spawned a novelization, which in turn was made into a made-for-television film of the same name in 2002, but has been included on lists of the worst Christmas songs of all time. After a single week in the top spot, "The Christmas Shoes" was replaced at number one by "This I Promise You" by NSYNC, which spent eleven consecutive weeks at number one after topping the chart for the first time for the last week of 2000. After being displaced from the top spot in the issue dated March 31, it returned to number one for a further week, giving it a final total of thirteen weeks in the top spot (twelve of them in 2001). This placed it in a tie for the highest total number of weeks spent at number one during 2001 with "There You'll Be" by Faith Hill, a song from the soundtrack of the film Pearl Harbor, which also spent twelve non-consecutive weeks at number one. With the exception of "The Christmas Shoes", all of 2001's number ones had multiple runs atop the chart, including the British singer Dido's "Thank You", which reached the top spot on four occasions, but spent only a single week at number one each time.
In the last quarter of the year, two songs that came to be associated with coverage of the September 11 attacks topped the chart. The first was "Only Time" by Irish musician Enya, which reached the top spot in the issue of Billboard dated September 29. The song, originally released in 2000, was used in a video paying tribute to the victims of the attacks that went viral on the internet and was featured on television, and it went on to spend six non-consecutive weeks atop the AC chart. It was replaced at number one in early December by "Hero" by Enrique Iglesias, another song that came to be associated with the aftermath of the attacks. The song, which Iglesias performed on the ' telethon on September 21, and which became ubiquitous in the weeks after the attacks as what MTV later called an "impromptu anthem of healing", held the top spot for the final four weeks of the year.