This is a list of songs which reached number one on the Billboard Pop Airplay chart in 2021.
During 2021, a total of 13 singles hit number-one on the charts.
| † | Indicates best-performing song of 2021 [1] |
| Issue date | Song | Artist(s) | Ref. |
|---|---|---|---|
| January 2 | "Positions" | Ariana Grande | [2] |
| January 9 | [3] | ||
| January 16 | [4] | ||
| January 23 | [5] | ||
| January 30 | [6] | ||
| February 6 | [7] | ||
| February 13 | "34+35" | [8] | |
| February 20 | [9] | ||
| February 27 | [10] | ||
| March 6 | "Drivers License" | Olivia Rodrigo | [11] |
| March 13 | [12] | ||
| March 20 | [13] | ||
| March 27 | [14] | ||
| April 3 | [15] | ||
| April 10 | "Therefore I Am" | Billie Eilish | [16] |
| April 17 | [17] | ||
| April 24 | "Save Your Tears" | The Weeknd | [18] |
| May 1 | [19] | ||
| May 8 | [20] | ||
| May 15 | [21] | ||
| May 22 | "Peaches" | Justin Bieber featuring Daniel Caesar and Giveon | [22] |
| May 29 | [23] | ||
| June 5 | [24] | ||
| June 12 | [25] | ||
| June 19 | "Levitating" † | Dua Lipa featuring DaBaby | [26] |
| June 26 | [27] | ||
| July 3 | [28] | ||
| July 10 | "Kiss Me More" | Doja Cat featuring SZA | [29] |
| July 17 | "Montero (Call Me by Your Name)" | Lil Nas X | [30] |
| July 24 | "Good 4 U" | Olivia Rodrigo | [31] |
| July 31 | [32] | ||
| August 7 | [33] | ||
| August 14 | [34] | ||
| August 21 | [35] | ||
| August 28 | [36] | ||
| September 4 | "Stay" | The Kid Laroi and Justin Bieber | [37] |
| September 11 | [38] | ||
| September 18 | [39] | ||
| September 25 | [40] | ||
| October 2 | [41] | ||
| October 9 | [42] | ||
| October 16 | [43] | ||
| October 23 | [44] | ||
| October 30 | [45] | ||
| November 6 | [46] | ||
| November 13 | [47] | ||
| November 20 | "Industry Baby" | Lil Nas X and Jack Harlow | [48] |
| November 27 | "Stay" | The Kid Laroi and Justin Bieber | [49] |
| December 4 | [50] | ||
| December 11 | "Easy on Me" | Adele | [51] |
| December 18 | [52] | ||
| December 25 | [53] |