These are the Irish Recorded Music Association's number one albums of 2003, per the Top 100 Individual Artist Albums chart.
| Issue Date | Album | Artist |
|---|---|---|
| 2 January | Let Go | Avril Lavigne |
| 9 January | Missundaztood | Pink |
| 16 January | Let Go | Avril Lavigne |
| 23 January | ||
| 30 January | Justified | Justin Timberlake |
| 6 February | ||
| 13 February | 100th Window | Massive Attack |
| 20 February | Come Away with Me | Norah Jones |
| 27 February | ||
| 6 March | ||
| 13 March | ||
| 20 March | ||
| 27 March | Meteora | Linkin Park |
| 3 April | Come Away with Me | Norah Jones |
| 10 April | ||
| 17 April | ||
| 24 April | ||
| 1 May | Justified | Justin Timberlake |
| 8 May | ||
| 15 May | ||
| 22 May | Set List | The Frames |
| 29 May | ||
| 3 June | You Gotta Go There to Come Back | Stereophonics |
| 12 June | Hail to the Thief | Radiohead |
| 19 June | St. Anger | Metallica |
| 26 June | Dangerously in Love | Beyoncé |
| 3 July | So Much for the City | The Thrills |
| 10 July | ||
| 17 July | ||
| 24 July | ||
| 31 July | ||
| 7 August | ||
| 14 August | Sometimes Right, Sometimes Wrong | Mickey Joe Harte |
| 21 August | ||
| 28 August | ||
| 4 September | So Much for the City | The Thrills |
| 11 September | Square 1 | David Kitt |
| 18 September | ||
| 25 September | ||
| 2 October | Life for Rent | Dido |
| 9 October | ||
| 16 October | ||
| 23 October | ||
| 30 October | In Time: The Best of R.E.M. 1988–2003 | R.E.M. |
| 6 November | ||
| 13 November | ||
| 20 November | ||
| 27 November | Turnaround | Westlife |
| 4 December | ||
| 11 December | Number Ones | Michael Jackson |
| 18 December | Life for Rent | Dido |
| 25 December |