List of number-one singles of 2019 (Australia)
The ARIA Singles Chart ranks the best-performing singles in Australia. Its data, published by the Australian Recording Industry Association, is based collectively on the weekly physical and digital sales and streams of singles. In 2019, 10 songs reached number one, with "Dance Monkey" by Tones and I the longest-running. Six acts, Swae Lee, Jonas Brothers, Billie Eilish, Lil Nas X, Shawn Mendes and Tones and I, reached the top spot for the first time. With 10 weeks atop the chart, Tones and I's song "Dance Monkey" broke the record for the most weeks at number one by an Australian artist, which was previously held by Justice Crew's 2014 song "Que Sera". In November, the song reached 16 weeks at number one, breaking the record for most weeks at number one in Australian chart history, previous held by Ed Sheeran's "Shape of You". It spent 21 weeks atop the chart.
earned her third number 1 single in 2019 with "7 Rings", it spent five weeks at number one.
earned her first number 1 single with Bad Guy". It spent two weeks at number 1 in April 2019.
reached number 1 with his debut single "Old Town Road", spending thirteen non-consecutive weeks at number 1.
returned to number 1 a year later with her 1994 single, "All I Want for Christmas Is You" which first topped the chart in December 2018. It was the final single to top the chart in 2019 and the final number 1 single of the 2010s.
Chart history
| Issue date | Song | Artist | |
| 7 January | "Sunflower" | Post Malone and Swae Lee | |
| 14 January | "Sunflower" | Post Malone and Swae Lee | |
| 21 January | "Sunflower" | Post Malone and Swae Lee | |
| 28 January | "7 Rings" | Ariana Grande | |
| 4 February | "7 Rings" | Ariana Grande | |
| 11 February | "7 Rings" | Ariana Grande | |
| 18 February | "7 Rings" | Ariana Grande | |
| 25 February | "7 Rings" | Ariana Grande | |
| 4 March | "Shallow" | Lady Gaga and Bradley Cooper | |
| 11 March | "Shallow" | Lady Gaga and Bradley Cooper | |
| 18 March | "Sucker" | Jonas Brothers | |
| 25 March | "Sucker" | Jonas Brothers | |
| 1 April | "Sucker" | Jonas Brothers | |
| 8 April | "Bad Guy" | Billie Eilish | |
| 15 April | "Bad Guy" | Billie Eilish | |
| 22 April | "Old Town Road" | Lil Nas X | |
| 29 April | "Old Town Road" | Lil Nas X | |
| 6 May | "Old Town Road" | Lil Nas X | |
| 13 May | "Old Town Road" | Lil Nas X | |
| 20 May | "I Don't Care" | Ed Sheeran and Justin Bieber | |
| 27 May | "Old Town Road" | Lil Nas X | |
| 3 June | "Old Town Road" | Lil Nas X | |
| 10 June | "Old Town Road" | Lil Nas X | |
| 17 June | "Old Town Road" | Lil Nas X | |
| 24 June | "Old Town Road" | Lil Nas X | |
| 1 July | "Old Town Road" | Lil Nas X | |
| 8 July | "Old Town Road" | Lil Nas X | |
| 15 July | "Old Town Road" | Lil Nas X | |
| 22 July | "Old Town Road" | Lil Nas X | |
| 29 July | "Señorita" | Shawn Mendes and Camila Cabello | |
| 5 August | "Dance Monkey" | Tones and I | |
| 12 August | "Dance Monkey" | Tones and I | |
| 19 August | "Dance Monkey" | Tones and I | |
| 26 August | "Dance Monkey" | Tones and I | |
| 2 September | "Dance Monkey" | Tones and I | |
| 9 September | "Dance Monkey" | Tones and I | |
| 16 September | "Dance Monkey" | Tones and I | |
| 23 September | "Dance Monkey" | Tones and I | |
| 30 September | "Dance Monkey" | Tones and I | |
| 7 October | "Dance Monkey" | Tones and I | |
| 14 October | "Dance Monkey" | Tones and I | |
| 21 October | "Dance Monkey" | Tones and I | |
| 28 October | "Dance Monkey" | Tones and I | |
| 4 November | "Dance Monkey" | Tones and I | |
| 11 November | "Dance Monkey" | Tones and I | |
| 18 November | "Dance Monkey" | Tones and I | |
| 25 November | "Dance Monkey" | Tones and I | |
| 2 December | "Dance Monkey" | Tones and I | |
| 9 December | "Dance Monkey" | Tones and I | |
| 16 December | "Dance Monkey" | Tones and I | |
| 23 December | "Dance Monkey" | Tones and I | |
| 30 December | "All I Want for Christmas Is You" | Mariah Carey |