List of number-one albums of 2005 (Ireland)

The following is a list of albums that reached the number-one position on the Irish Albums Chart in 2005. The Irish Albums Chart is compiled by the Irish Recorded Music Association (IRMA) on behalf of the Irish record industry. The chart is based on sales of physical and digital albums in Ireland. The dates listed represent the issue date of the chart.

• January 6 – How to Dismantle an Atomic Bomb – U2
• January 13 – Encore – Eminem
• January 20 – Greatest Hits – Robbie Williams
• January 27 – American Idiot – Green Day
• February 3 – Encore – Eminem
• February 10 – American Idiot – Green Day
• February 17 – American Idiot – Green Day
• February 24 – American Idiot – Green Day
• March 3 – American Idiot – Green Day
• March 10 – American Idiot – Green Day
• March 17 – American Idiot – Green Day
• March 24 – American Idiot – Green Day
• March 31 – American Idiot – Green Day
• April 7 – American Idiot – Green Day
• April 14 – American Idiot – Green Day
• April 21 – American Idiot – Green Day
• April 28 – American Idiot – Green Day
• May 5 – American Idiot – Green Day
• May 12 – X&Y – Coldplay
• May 19 – X&Y – Coldplay
• May 26 – X&Y – Coldplay
• June 2 – X&Y – Coldplay
• June 9 – X&Y – Coldplay
• June 16 – Out of Exile – Audioslave
• June 23 – X&Y – Coldplay
• June 30 – The Massacre – 50 Cent
• July 7 – Funeral – Arcade Fire
• July 14 – Employment – Kaiser Chiefs
• July 21 – Employment – Kaiser Chiefs
• July 28 – Employment – Kaiser Chiefs
• August 4 – Employment – Kaiser Chiefs
• August 11 – Employment – Kaiser Chiefs
• August 18 – Employment – Kaiser Chiefs
• August 25 – Employment – Kaiser Chiefs
• September 1 – Late Registration – Kanye West
• September 8 – Employment – Kaiser Chiefs
• September 15 – Have a Nice Day – Bon Jovi
• September 22 – Have a Nice Day – Bon Jovi
• September 29 – Have a Nice Day – Bon Jovi
• October 6 – Have a Nice Day – Bon Jovi
• October 13 – In Between Dreams – Jack Johnson
• October 20 – In Between Dreams – Jack Johnson
• October 27 – Confessions on a Dance Floor – Madonna
• November 3 – Confessions on a Dance Floor – Madonna
• November 10 – Confessions on a Dance Floor – Madonna
• November 17 – Confessions on a Dance Floor – Madonna
• November 24 – Confessions on a Dance Floor – Madonna
• December 1 – Confessions on a Dance Floor – Madonna
• December 8 – Confessions on a Dance Floor – Madonna
• December 15 – Ancora – Il Divo
• December 22 – The Love Album – Westlife
• December 29 – The Love Album – Westlife