The court announced that President Ali Bongo Ondimba would nominate a new ministerial team answerable directly to him, the court’s head Madeleine Mborantsuo said.
“It is clear that the government has not been able to fulfil the tasks assigned to it,” Mborantsuo said in a statement seen by AFP.
According to the court, the government should have organised twice-delayed elections by April 30 at the latest.
The powers of the disbanded National Assembly will be transferred to the upper house Senate until elections are held, the court added. A date for the ballot is yet to be announced.
President Ali Bongo’s re-election in 2016 led to opposition accusations of electoral fraud.
Violence broke out days after the vote, and opposition figures say more than 50 people were killed in clashes. The official toll was only three dead.
Bongo took over power from his father Omar Bongo, who ruled for 41 years until his death in 2009.
Gabon has large oil, mineral and tropical timber resources, and its per-capita national income is four times greater than that of most sub-Saharan nations.
But about a third of its population of 1.8 million still live below the poverty line — the result, say experts, of inequality, poor governance and corruption.