Mahmoud Ahmadinejad (Persian: محمود احمدی نژاد, Mahmūd Ahmadinezhād (help·info); born 28 October 1956) is the sixth and current President of the Islamic Republic of Iran, and the main political leader of the Alliance of Builders of Islamic Iran, a coalition of conservative political groups in the country. An engineer and teacher from a poor background, Ahmadinejad joined the Office for Strengthening Unity after the Islamic Revolution. Appointed a provincial governor, he was removed after the election of President Mohammad Khatami and returned to teaching. Tehran's council appointed him mayor in 2003. He took a religious hard-line, reversing reforms of previous moderate mayors. His 2005 presidential campaign, supported by the Alliance of Builders of Islamic Iran, garnered 62% of the runoff election votes, and he became President on 3 August 2005.

Ahmadinejad is a controversial figure both within Iran and internationally. He has been criticized domestically for his economic lapses and disregard for human rights. He launched a gas rationing plan in 2007 to reduce the country's fuel consumption, and cut the interest rates private and public banking facilities could charge. He supports Iran's nuclear energy program. His election to a second term in 2009 was widely disputed and caused widespread protests domestically and drew significant international criticism. Major opposition parties, traditional clerical circles and influential Iranian politicians questioned the legitimacy of his presidency.

Ahmadinejad is an outspoken critic of the United States, Israel, and United Kingdom. He abides by Iran's long-standing policy of refusing to recognize Israel as a legitimate nation or as representative of the region's population. He advocates "free elections" for the region, and believes Palestinians need a stronger voice in the region's future. He has been characterized in much of the West by a particular comment he made in 2005 which was initially translated as calling for the "occupying regime" (taken to mean Israel) to be "wiped off the map." However, other sources have suggested that a more accurate translation would be "this regime occupying Jerusalem must vanish (or 'be eliminated' ) from the page of time". He has also been accused of describing the Holocaust as a myth and of making statements influenced by classic anti-Semitic ideas, which has led to accusations of anti-Semitism, though he has rejected accusations of anti-Semitism and Holocaust denial, saying that he "respects Jews very much" and that he was not "passing judgment" on the Holocaust, consistently refocusing the debate onto the plight of the Palestinians which Ahmadinejad insists is the immediate global issue.