The Guardian Council, the Islamic Republic's constitutional watchdog, which reports directly to Iran's Supreme Leader Ayatollah Ali Khamenei, has approved the date earlier proposed by the interior ministry.
It will be the 10th presidential election in Iran since the 1979 Islamic Revolution.
According to local observers, the main intrigue of the upcoming election campaign will be whether the incumbent President Mahmoud Ahmadinejad, known for his uncompromising approach on Iran's nuclear issue, would be re-elected for a second four-year term.
Ahmadinejad, 51, who has been criticized by the opposition in the country for his failure to curb high inflation, estimated at about 27% annually, has not yet announced his candidacy for the 2009 election.
Among his potential rivals are former parliament speaker Mehdi Karroubi, who is the leader of the reformist National Confidence Party, and Mohammad-Bagher Ghalibaf, the 46-year-old mayor of Tehran, who enjoys the support of moderate conservatives.
Ahmadinejad's pro-reform opponents have called for more diplomacy in relations with the West over Iran's controversial uranium enrichment program.
Western countries suspect Iran of pursuing a secret nuclear weapons program, but the country says it needs nuclear power solely for civilian purposes.
The Islamic Republic which holds the world's third-largest proven oil reserves, is already under three sets of UN sanctions over suspicions it seeks to build nuclear weapons under the guise of a civilian program. It is facing more stringent punitive measures for its refusal to halt uranium enrichment.
