Kalosil had been in the job since March last year and survived three previous attempts to remove him from office, the Australian Broadcasting Corporation said.
Hilaire Bule, a journalist on the Vanuatu Independent, said Natuman won 40 out of the 52 votes cast by parliamentarians.
"Joe Natuman is now our new prime minister. He is selecting his ministers," he told AFP of a man who has served in various governments and held a variety of ministerial positions, including foreign affairs and justice.
But a decision to pick little-known Singaporean company, Vanuatu Trade Development, to build and run an expensive new international airport caused friction.
