Abiy himself does not live there, and it has seen little activity in recent years.
Abiy's advisers say he has taken a keen interest in transforming the palace into a tourist attraction since Online Cigarettes Store USA coming to power in April 2018 -- visiting the site every day in recent weeks to monitor progress.
The government's "Home-Grown Economic Reform" agenda, unveiled last month, describes tourism Newport Pleasure as a primary engine of potential job creation.
On Thursday, government officials and the diplomatic corps toured the expansive site before attending a banquet that was expected to draw five regional heads of state and other dignitaries.
The restored rooms feature items like Menelik's sword and a life-size wax replica of former Emperor Haile Selassie, who lived at the palace and was then detained there after the Derg overthrew him in 1974.
The site also includes a sculpture garden with installations representing Ethiopia's nine regions, Newport 100s Box and a zoo is expected to open by the end of the year.
Aklilu Fikresilassie, an Ethiopian employee of the United Nations who attended the launch Thursday, said he was "really fascinated" to set foot inside a place that had been closed to the public his entire life.