Prime Minister Prayuth Chan-ocha told reporters in Bangkok the election would be in November 2018 and the exact date will be announced next June.
Prayuth led the May 2014 coup that ousted Prime Minister Yingluck Shinawatra's government, ending years of political instability and violent protests. The ruling junta has announced several dates for new elections during its rule, but has repeatedly canceled them as it drafted a new constitution.
The prime minister also said the junta was considering whether to allow political activity - which it suspended after taking office - to resume after funeral services later this month for King Bhumibol Adulyadej, who died last year.
The coup that overthrew Yingluck Shinawatra capped a decade-long period of political turmoil that began when her brother, former Prime Minister Thaksin Shinawatra, was himself forced out of office in 2006 by the military, which backed Thailand's Bangkok-based royalist-leaning, wealthy elite.
FILE - Former Thai Prime Minister Thaksin Shinawatra speaks to Reuters during an interview in Singapore, Feb. 23, 2016.
The anti-Thaksin forces, who protested in the streets of Bangkok wearing yellow shirts, gave rise to the pro-Thaksin Red Shirts, whose ranks included the rural poor who strongly supported Thaksin's policies. The two sides engaged in violent, sometimes deadly clashes in the streets of Bangkok during that era.
Thaksin himself has lived in exile since 2008 to avoid corruption charges brought against him.
Yingluck was convicted by Thailand's supreme court late last month on charges of negligence in connection with a botched rice buying program and sentenced in absentia to five years in prison. The verdict was initially scheduled to be issued last month, but Yingluck failed to appear for the hearing. Prime Minister Prayuth later said Yingluck had fled to Dubai to escape a prison sentence.
Yingluck has denied the charges, claiming they were politically motivated.