Authorities did not immediately announce the cause of Meles' death, but the prime minister hadn't been seen in public in Ethiopia in several weeks.
State TV announced the death on Tuesday.
It said Meles died just before midnight on Monday after contracting an infection.
The most recent images of Meles aired by state-run Ethiopian Television showed him noticeably thinner.
State TV said the country's Deputy Prime Minister Hailemariam Desalegn was put in charge of the cabinet.