Morrison beat Peter Dutton 45 to 40 in a secret ballot, according to the Sydney Morning Herald newspaper. Dutton, a former home affairs minister, initiated the vote.
Previously, Dutton called for a new closed-door party meeting, in a challenge against Turnbull.
The Australian government has been in turmoil after an exodus of ministers emphasized Turnbull’s waning support in his own party, which is a senior member in the ruling coalition. He narrowly won a leadership vote on Tuesday.