| Election Name: | 2009 Dún Laoghaire–Rathdown County Council election |
| Country: | Ireland |
| Type: | Parliamentary |
| Ongoing: | no |
| Party Colour: | yes |
| Previous Election: | 2004 Dún Laoghaire–Rathdown County Council election |
| Previous Year: | 2004 |
| Next Election: | 2014 Dún Laoghaire–Rathdown County Council election |
| Next Year: | 2014 |
| Seats For Election: | 28 seats on Dún Laoghaire–Rathdown County Council |
| Election Date: | 5 June 2009 |
| Party1: | Fine Gael |
| Seats1: | 11 |
| Seat Change1: | +2 |
| Party2: | Labour Party (Ireland) |
| Seats2: | 8 |
| Seat Change2: | +2 |
| Party3: | Fianna Fáil |
| Seats3: | 4 |
| Seat Change3: | -3 |
| Party4: | People Before Profit Alliance |
| Seats4: | 2 |
| Seat Change4: | +2 |
| Party5: | Independent (politician) |
| Seats5: | 3 |
| Seat Change5: | +2 |
| Party6: | Green Party (Ireland) |
| Seats6: | 0 |
| Seat Change6: | -4 |
| Map Size: | 300px |
| Council control | |
| Posttitle: | Council control after election |
An election to all 28 seats on Dún Laoghaire–Rathdown County Council took place on 5 June 2009 as part of the 2009 Irish local elections. Councillors were elected from six local electoral areas for a five-year term of office on the electoral system of proportional representation by means of the single transferable vote (PR-STV).
| Party | valign=top | Seats | valign=top | ± | valign=top | First Pref. votes | valign=top | FPv% | valign=top | ±% |
|---|---|---|---|---|---|---|---|---|---|---|
| 11 | +2 | 28,754 | 34.35 | |||||||
| 8 | +2 | 19,094 | 22.81 | |||||||
| 4 | align=right | -3 | 13,116 | 15.67 | ||||||
| 3 | +2 | 9,061 | 10.82 | |||||||
| 2 | +2 | 6,266 | 7.49 | |||||||
| 0 | align=right | -4 | 5,260 | 6.28 | ||||||
| 0 | align=right | -1 | align=right | - | align=right | - | ||||
| Totals | align=right | 28 | align=center | - | align=right | 83,708 | 100.00 | — |