It was found just 50 m from a family's house in Tan Ky District on Monday, and authorities quickly put up warning signs to keep people out of the area.
On Tuesday engineers from the military headquarters of Nghe An extracted the bomb, which measured 1.2 m in length, and took it to Tan Long Commune for safe disposal.
Authorities said it was a Vietnam War relic.
Tan Ky District was frequently bombed during the war.
Since 1975, when the war ended, more than 40,000 people in Vietnam have been killed and 60,000 others have been injured by unexploded ordnance (UXO).
Around 800,000 tons of UXO remain scattered across the country, the National Steering Committee on Overcoming Post-War Unexploded Ordnance and Toxic Chemical Consequences had said in 2018.
Vietnam is one of the most heavily contaminated countries in the world, it had added.