# List of Ultratop 50 number-one singles of 2021

These hits topped the Ultratop 50 in 2021.
Flanders :
| Issue date | Song | Artist |
| 2 January | "Nu wij niet meer praten" | Jaap Reesema and Pommelien Thijs |
| 9 January | "Fever" | Dua Lipa and Angèle |
| 16 January | "Fever" | Dua Lipa and Angèle |
| 23 January | "Drivers License" | Olivia Rodrigo |
| 30 January | "Drivers License" | Olivia Rodrigo |
| 6 February | "Drivers License" | Olivia Rodrigo |
| 13 February | "Drivers License" | Olivia Rodrigo |
| 20 February | "Drivers License" | Olivia Rodrigo |
| 27 February | "Drivers License" | Olivia Rodrigo |
| 6 March | "Save Your Tears" | The Weeknd |
| 13 March | "Wellerman" | Nathan Evans |
| 20 March | "Without You" | The Kid Laroi |
| 27 March | "Wellerman" | Nathan Evans |
| 3 April | "Wellerman" | Nathan Evans |
| 10 April | "Friday" | Riton and Nightcrawlers featuring Mufasa & Hypeman |
| 17 April | "Wellerman" | Nathan Evans |
| 24 April | "1 op een miljoen" | Metejoor featuring Babet |
| 1 May | "Friday" | Riton and Nightcrawlers featuring Mufasa & Hypeman |
| 8 May | "De wereld draait voor jou" | Niels Destadsbader and Regi |
| 15 May | "De wereld draait voor jou" | Niels Destadsbader and Regi |
| 22 May | "Higher Power" | Coldplay |
| 29 May | "The Wrong Place" | Hooverphonic |
| 5 June | "Good 4 U" | Olivia Rodrigo |
| 12 June | "Good 4 U" | Olivia Rodrigo |
| 19 June | "Good 4 U" | Olivia Rodrigo |
| 26 June | "Good 4 U" | Olivia Rodrigo |
| 3 July | "Good 4 U" | Olivia Rodrigo |
| 10 July | "Bad Habits" | Ed Sheeran |
| 17 July | "Bad Habits" | Ed Sheeran |
| 24 July | "Bad Habits" | Ed Sheeran |
| 31 July | "Bad Habits" | Ed Sheeran |
| 7 August | "Bad Habits" | Ed Sheeran |
| 14 August | "Bad Habits" | Ed Sheeran |
| 21 August | "Bad Habits" | Ed Sheeran |
| 28 August | "Love Tonight" | Shouse |
| 4 September | "Love Tonight" | Shouse |
| 11 September | "Love Tonight" | Shouse |
| 18 September | "Love Tonight" | Shouse |
| 25 September | "Love Tonight" | Shouse |
| 2 October | "Love Tonight" | Shouse |
| 9 October | "Stay" | The Kid Laroi and Justin Bieber |
| 16 October | "Stay" | The Kid Laroi and Justin Bieber |
| 23 October | "Easy on Me" | Adele |
| 30 October | "Easy on Me" | Adele |
| 6 November | "Easy on Me" | Adele |
| 13 November | "Easy on Me" | Adele |
| 20 November | "Easy on Me" | Adele |
| 27 November | "Easy on Me" | Adele |
| 4 December | "Easy on Me" | Adele |
| 11 December | "Easy on Me" | Adele |
| 18 December | "Easy on Me" | Adele |
| 25 December | "Waterval" | K3 |
Wallonia :
| Issue date | Song | Artist |
| 2 January | "Fever" | Dua Lipa and Angèle |
| 9 January | "Fever" | Dua Lipa and Angèle |
| 16 January | "Fever" | Dua Lipa and Angèle |
| 23 January | "Fever" | Dua Lipa and Angèle |
| 30 January | "Fever" | Dua Lipa and Angèle |
| 6 February | "Fever" | Dua Lipa and Angèle |
| 13 February | "Fever" | Dua Lipa and Angèle |
| 20 February | "Fever" | Dua Lipa and Angèle |
| 27 February | "Fever" | Dua Lipa and Angèle |
| 6 March | "Save Your Tears" | The Weeknd |
| 13 March | "Fever" | Dua Lipa and Angèle |
| 20 March | "Save Your Tears" | The Weeknd |
| 27 March | "Save Your Tears" | The Weeknd |
| 3 April | "Save Your Tears" | The Weeknd |
| 10 April | "Save Your Tears" | The Weeknd |
| 17 April | "Save Your Tears" | The Weeknd |
| 24 April | "Save Your Tears" | The Weeknd |
| 1 May | "Save Your Tears" | The Weeknd |
| 8 May | "Morose" | Damso |
| 15 May | "Save Your Tears" | The Weeknd |
| 22 May | "Save Your Tears" | The Weeknd |
| 29 May | "Save Your Tears" | The Weeknd |
| 5 June | "Save Your Tears" | The Weeknd |
| 12 June | "Cover Me in Sunshine" | Pink and Willow Sage Hart |
| 19 June | "Petrouchka" | Soso Maness featuring PLK |
| 26 June | "Petrouchka" | Soso Maness featuring PLK |
| 3 July | "Cover Me in Sunshine" | Pink and Willow Sage Hart |
| 10 July | "Cover Me in Sunshine" | Pink and Willow Sage Hart |
| 17 July | "Cover Me in Sunshine" | Pink and Willow Sage Hart |
| 24 July | "Cover Me in Sunshine" | Pink and Willow Sage Hart |
| 31 July | "Never Going Home" | Kungs |
| 7 August | "Bad Habits" | Ed Sheeran |
| 14 August | "Bad Habits" | Ed Sheeran |
| 21 August | "Bad Habits" | Ed Sheeran |
| 28 August | "Bad Habits" | Ed Sheeran |
| 4 September | "Bad Habits" | Ed Sheeran |
| 11 September | "Bad Habits" | Ed Sheeran |
| 18 September | "Bad Habits" | Ed Sheeran |
| 25 September | "Bad Habits" | Ed Sheeran |
| 2 October | "Stay" | The Kid Laroi and Justin Bieber |
| 9 October | "Bad Habits" | Ed Sheeran |
| 16 October | "Stay" | The Kid Laroi and Justin Bieber |
| 23 October | "Santé" | Stromae |
| 30 October | "Bruxelles je t'aime" | Angèle |
| 6 November | "Cold Heart (Pnau remix)" | Elton John and Dua Lipa |
| 13 November | "Bruxelles je t'aime" | Angèle |
| 20 November | "Cold Heart (Pnau remix)" | Elton John and Dua Lipa |
| 27 November | "Easy on Me" | Adele |
| 4 December | "Easy on Me" | Adele |
| 11 December | "Bruxelles je t'aime" | Angèle |
| 18 December | "Bruxelles je t'aime" | Angèle |
| 25 December | "Bruxelles je t'aime" | Angèle |
Flanders Ranking of most weeks at number 1 :
| Position | Artist | Weeks #1 |
Wallonia Ranking of most weeks at number 1 :
| Position | Artist | Weeks #1 |