This is a list of singles which topped the Irish Singles Chart in 1966.
Note that prior to 1992, the Irish singles chart was compiled from trade shipments from the labels to record stores, rather than on consumer sales.
| Issue Date | Song | Artist | Ref. |
|---|---|---|---|
| 3 January | "Day Tripper" | The Beatles | |
| 10 January | |||
| 17 January | |||
| 24 January | "Lovely Leitrim" | Larry Cunningham | |
| 31 January | |||
| 7 February | "Old Man Trouble" | Doc Carroll and the Royal Blues | |
| 14 February | |||
| 21 February | "These Boots Are Made for Walkin'" | Nancy Sinatra | |
| 28 February | "Come Back To Stay" | Dickie Rock | |
| 7 March | |||
| 14 March | |||
| 21 March | |||
| 28 March | "The Sea Around Us" | The Ludlows | |
| 4 April | |||
| 11 April | |||
| 18 April | |||
| 25 April | "Black and Tan Gun" | The Johnny Flynn Showband with Pat Smith | |
| 2 May | |||
| 9 May | "Pretty Flamingo" | Manfred Mann | |
| 16 May | |||
| 23 May | |||
| 30 May | |||
| 6 June | "Strangers in the Night" | Frank Sinatra | |
| 13 June | |||
| 20 June | "Paperback Writer" | The Beatles | [1] |
| 27 June | |||
| 4 July | |||
| 11 July | |||
| 18 July | "Sunny Afternoon" | The Kinks | |
| 25 July | "More Than Yesterday" | Gregory & The Cadets | |
| 1 August | |||
| 8 August | |||
| 15 August | "Travelling People" | The Johnstons | |
| 22 August | "Yellow Submarine" | The Beatles | |
| 29 August | |||
| 5 September | "Pretty Brown Eyes" | Joe Dolan | |
| 12 September | |||
| 19 September | |||
| 26 September | "The Merry Ploughboy (Off To Dublin In The Green)" | Dermot O'Brien | |
| 3 October | |||
| 10 October | |||
| 17 October | |||
| 24 October | |||
| 31 October | |||
| 7 November | "Somewhere My Love" | Charlie Matthews & The Royal Showband | |
| 14 November | "Mursheen Durkin" | Johnny McEvoy | |
| 21 November | |||
| 28 November | |||
| 5 December | "Green, Green Grass of Home" | Tom Jones | |
| 12 December | |||
| 19 December | |||
| 26 December |