Reform in Myanmar (also called Burma) has been under way since 2010 when military rule was replaced by a military-backed civilian government.
The ruling USDP faces a head-to-head contest with Aung San Suu Kyi's National League for Democracy. She won elections in 1990 that were scrapped. Dozens of other parties are also expected to take part in the vote.
The election commission announcement, posted on its website, confirmed what a senior election official had told the BBC earlier on Wednesday.
The NLD won the last free general election in Myanmar in 1990 but the then-ruling military junta ignored the results.
The party boycotted a national election in 2010 because its leader was barred from standing.
Eighty-three parties are likely to contest the polls and a quarter of the 664 parliamentary seats will be reserved for the military.
A president will be chosen by parliament after the election but under the constitution Ms Suu Kyi is barred from taking the top job because her late husband was British and her two sons are British citizens.
Two weeks ago parliamentarians voted down a motion to amend this clause. They also voted to keep the army's veto over constitutional change, dealing a blow to hopes for fuller democracy.
The NLD has said it will formally announce if it intends to stand within three days of the election date officially being announced.
But Soe Win Than of the BBC Burmese Service reports all political parties must contest at least three constituencies to exist as a party.
He adds it is the first time in many decades a general election will be held with "the potential widest participation by the many opposition parties".
Ms Suu Kyi campaigned door to door on Saturday in Yangon and has hinted she will stand.
