List of Ultratop 40 number-one singles of 2009
# List of Ultratop 40 number-one singles of 2009

This is a list of songs that topped the Belgian Walloon (francophone) Ultratop 40 in 2009.

| Issue date | Song title | Artist |
| - | - | - |
| January 3 | "Toi + Moi" | Grégoire |
| January 10 | "Toi + Moi" | Grégoire |
| January 17 | "Toi + Moi" | Grégoire |
| January 24 | "Toi + Moi" | Grégoire |
| January 31 | "Hot n Cold" | Katy Perry |
| February 7 | "Hot n Cold" | Katy Perry |
| February 14 | "Poker Face" | Lady Gaga |
| February 21 | "Poker Face" | Lady Gaga |
| February 28 | "Poker Face" | Lady Gaga |
| March 7 | "Poker Face" | Lady Gaga |
| March 14 | "Poker Face" | Lady Gaga |
| March 21 | "Poker Face" | Lady Gaga |
| March 28 | "Ici les Enfoirés" | Les Enfoirés |
| April 4 | "Poker Face" | Lady Gaga |
| April 11 | "Poker Face" | Lady Gaga |
| April 18 | "Poker Face" | Lady Gaga |
| April 25 | "Right Round" | Flo Rida featuring Ke$ha |
| May 2 | "Broken Strings" | James Morrison featuring Nelly Furtado |
| May 9 | "C'est dit" | Calogero |
| May 16 | "C'est dit" | Calogero |
| May 23 | "C'est dit" | Calogero |
| May 30 | "Boom Boom Pow" | The Black Eyed Peas |
| June 6 | "Boom Boom Pow" | The Black Eyed Peas |
| June 13 | "Boom Boom Pow" | The Black Eyed Peas |
| June 20 | "Boom Boom Pow" | The Black Eyed Peas |
| June 27 | "Boom Boom Pow" | The Black Eyed Peas |
| July 4 | "When Love Takes Over" | David Guetta featuring Kelly Rowland |
| July 11 | "When Love Takes Over" | David Guetta featuring Kelly Rowland |
| July 18 | "When Love Takes Over" | David Guetta featuring Kelly Rowland |
| July 25 | "When Love Takes Over" | David Guetta featuring Kelly Rowland |
| August 1 | "I Gotta Feeling" | The Black Eyed Peas |
| August 8 | "I Gotta Feeling" | The Black Eyed Peas |
| August 15 | "I Gotta Feeling" | The Black Eyed Peas |
| August 22 | "I Gotta Feeling" | The Black Eyed Peas |
| August 29 | "I Gotta Feeling" | The Black Eyed Peas |
| September 5 | "Sexy Bitch" | David Guetta featuring Akon |
| September 12 | "I Gotta Feeling" | Black Eyed Peas |
| September 19 | "Sexy Bitch" | David Guetta featuring Akon |
| September 26 | "I Gotta Feeling" | Black Eyed Peas |
| October 3 | "Alors on danse" | Stromae |
| October 10 | "Alors on danse" | Stromae |
| October 17 | "Alors on danse" | Stromae |
| October 24 | "Alors on danse" | Stromae |
| October 31 | "Alors on danse" | Stromae |
| November 7 | "I Gotta Feeling" | Black Eyed Peas |
| November 14 | "Sexy Bitch" | David Guetta featuring Akon |
| November 21 | "Meet Me Halfway" | The Black Eyed Peas |
| November 28 | "Meet Me Halfway" | The Black Eyed Peas |
| December 5 | "We Are The Best" | The Champions |
| December 12 | "We Are The Best" | The Champions |
| December 19 | "We Are The Best" | The Champions |
| December 26 | "Meet Me Halfway" | The Black Eyed Peas |
