Opposition Leader Cam Broten received approval of 98 per cent of members who cast ballots Saturday in Regina, the party says.
The vote is a requirement of the Saskatchewan NDP constitution.
The convention is the last the party will have before an expected election call in Saskatchewan next spring.
The party says Broten addressed the convention before the vote with about 475 people in the room.
After the vote, Broten tweeted that he was "truly honoured."
"I'll keep working hard to make you proud and build a better (Saskatchewan) for everyone," Broten tweeted.
Former New Democrat premiers Roy Romanow and Lorne Calvert were also scheduled to address the convention Saturday.
Some NDP members have said the outcome of the Alberta election is expected to re-energize the party and provide momentum before the next election.