This is a list of songs which reached number one on the Billboard Mainstream Top 40 (or Pop Songs) chart in 2017.
During 2017, a total of 18 singles hit number-one on the charts.
| † | Indicates best-performing single of 2017[1] |
| Issue date | Song | Artist(s) | Ref. |
|---|---|---|---|
| January 7 | "Side to Side" | Ariana Grande featuring Nicki Minaj | [2] |
| January 14 | [3] | ||
| January 21 | [4] | ||
| January 28 | "Don't Wanna Know" | Maroon 5 featuring Kendrick Lamar | [5] |
| February 4 | "Scars to Your Beautiful" | Alessia Cara | [6] |
| February 11 | [7] | ||
| February 18 | "Bad Things" | Machine Gun Kelly and Camila Cabello | [8] |
| February 25 | [9] | ||
| March 4 | "Shape of You" | Ed Sheeran | [10] |
| March 11 | [11] | ||
| March 18 | [12] | ||
| March 25 | [13] | ||
| April 1 | [14] | ||
| April 8 | [15] | ||
| April 15 | [16] | ||
| April 22 | [17] | ||
| April 29 | [18] | ||
| May 6 | "That's What I Like" | Bruno Mars | [19] |
| May 13 | [20] | ||
| May 20 | [21] | ||
| May 27 | "Something Just Like This" | The Chainsmokers and Coldplay | [22] |
| June 3 | [23] | ||
| June 10 | "Stay" | Zedd and Alessia Cara | [24] |
| June 17 | [25] | ||
| June 24 | [26] | ||
| July 1 | [27] | ||
| July 8 | [28] | ||
| July 15 | [29] | ||
| July 22 | "Despacito" | Luis Fonsi and Daddy Yankee featuring Justin Bieber | [30] |
| July 29 | [31] | ||
| August 5 | [32] | ||
| August 12 | [33] | ||
| August 19 | [34] | ||
| August 26 | "There's Nothing Holdin' Me Back" | Shawn Mendes | [35] |
| September 2 | [36] | ||
| September 9 | "Attention" | Charlie Puth | [37] |
| September 16 | [38] | ||
| September 23 | [39] | ||
| September 30 | [40] | ||
| October 7 | "Slow Hands" | Niall Horan | [41] |
| October 14 | "Strip That Down" | Liam Payne featuring Quavo | [42] |
| October 21 | [43] | ||
| October 28 | "Look What You Made Me Do" | Taylor Swift | [44] |
| November 4 | "Sorry Not Sorry" | Demi Lovato | [45] |
| November 11 | "Feel It Still" | Portugal. The Man | [46] |
| November 18 | [47] | ||
| November 25 | [48] | ||
| December 2 | "Thunder" | Imagine Dragons | [49] |
| December 9 | "Havana" | Camila Cabello featuring Young Thug | [50] |
| December 16 | [51] | ||
| December 23 | [52] | ||
| December 30 | [53] |
