The announcement said King Maha Vajiralongkorn had endorsed a decree to dissolve Parliament, ahead of an election that must be held 45 to 60 days after dissolution.
"This is a swift return of political decision-making power to the people to elect a democratic government with the King as head of state," the announcement said.
The election is expected to take place on May 7 or May 14.
The May general election will choose members of Parliament, which together with the Senate will select a prime minister by the end of July, with a cabinet named by early August, according to a timeline provided by the government.
The timeline after dissolution of Parliament: