| Election Name: | 2005 State of Mexico election |
| Country: | State of Mexico |
| Type: | presidential |
| Ongoing: | no |
| Election Date: | 3 July 2005 |
| Previous Election: | 1999 State of Mexico election |
| Previous Year: | 1999 |
| Next Election: | 2011 State of Mexico election |
| Next Year: | 2011 |
| Candidate1: | Enrique Peña Nieto |
| Party1: | Institutional Revolutionary Party |
| Alliance1: | Alliance for Mexico |
| Popular Vote1: | 1,639,233 |
| Percentage1: | 47.45 |
| Candidate2: | Rubén Mendoza Ayala |
| Party2: | National Action Party (Mexico) |
| Popular Vote2: | 856,591 |
| Percentage2: | 24.79 |
| Candidate3: | Yeidckol Polevnsky Gurwitz |
| Party3: | Party of the Democratic Revolution |
| Popular Vote3: | 835,182 |
| Percentage3: | 24.17 |
| Governor | |
| Before Election: | Arturo Montiel Rojas |
| Before Party: | Institutional Revolutionary Party |
| After Election: | Enrique Peña Nieto |
| After Party: | Institutional Revolutionary Party |
A gubernatorial election was held in the State of México on Sunday, 3 July 2005.Voters in Mexico's most populous state went to the polls to elect a governor to replace former incumbent Arturo Montiel Rojas of the Institutional Revolutionary Party (PRI).
The favorite candidate was PAN's Rubén Mendoza. It was thought the first runner-up would be PRD Yeidckol Polevnsky Gurwitz (born as Citlali Ibáñez Camacho) and last place by PRI's Enrique Peña. However, Rubén Mendoza made several mistakes in his campaign, appearing apparently drunk at events, boasting he led a group of supporters to steal campaign gifts from Peña's team and gave them with his own signature (he was taped while doing this). The PRD would have benefited from this, but Polevnksy had no political experience and support from Andrés Manuel López Obrador wasn't enough, specially after her true identity was discovered. So PRI's Peña rose to the first place, the PRD had a distant and low second place and PAN's Rubén Mendoza disappeared from public view.
Turnout was an unusually low 48%.
With 93.38% of the votes it was clear that the PRI had managed to keep hold of the state.
| Candidate | Party/Alliance | Votes | % | |
|---|---|---|---|---|
| Enrique Peña Nieto | Institutional Revolutionary Party &</small> Green Ecological Party of Mexico | 1,639,233 | 47.45 | |
| Rubén Mendoza Ayala | National Action Party &</small> Convergencia | 856,591 | 24.79 | |
| Yeidckol Polevnsky Gurwitz | Party of the Democratic Revolution &</small> Labour Party | 835,182 | 24.17 | |
| Total | 3,331,006 | 100% |