The elephant killed a 33-year old man, Suniram Baski, at Aamgachhi kurua village and a 25-year-old woman, Savati Tudu, at Silanda village in Jama block of the district, Divisional Forest Officer Abhishek Kumar said.
Another man suffered serious injuries in its attack at Kulapathar village and was admitted to a hospital in Dumka, he said.
The DFO said the elephant, which strayed from a herd and entered the villages late last night, also destroyed two houses.
A team has been sent to drive the animal into the forests, he added.