Mayo County Council: 1999 Local Election
| Party | Seats | Votes | Share | Candidates | Constituencies | |||||
| Fianna Fáil |  | 16 | (+1) | 26119 | 46.2% | (-1.1%) | 23 | (+1) | 7 | (+1) |
| Fine Gael |  | 13 | 23414 | 41.4% | (+1.5%) | 20 | (+1) | 7 | (+1) | |
| Independent |  | 1 | (-1) | 4814 | 8.5% | (+2.1%) | 8 | (+1) | 5 | (+1) |
| Labour Party |  | 1 | 1021 | 1.8% | (-1.8%) | 1 | (-3) | 1 | (-3) | |
| Sinn Féin |  | 0 | 860 | 1.5% | (+1.5%) | 2 | (+2) | 2 | (+2) | |
| Green Party |  | 0 | 336 | 0.6% | (+0.6%) | 3 | (+3) | 3 | (+3) | |