The party says that's a 35 per cent membership increase in the last year.
"We are pleased that the leadership contest has resulted in a substantial increase in our membership over last year," party president Cory Oxelgren said in a release on the party's website Tuesday.
“Many of these new members are former members who hadn’t renewed in some time, but a great many are first-time members."
Oxelgren said he's especially pleased that there's been a surge in membership among young people.
The deadline to become a member or renew membership passed on Friday.
The vote on March 9 is to replace former leader Dwain Lingenfelter, who resigned when he lost his seat in the 2011 provincial election.
John Nilson has been the interim leader, but is not seeking the top job.
The four candidates are MLAs Trent Wotherspoon and Cam Broten, Saskatoon doctor Ryan Meili and economist Erin Weir.
Oxelgren also said he is pleased at the amount of interest that has been shown at the leadership debates. The party is holding 14 such debates across the province before ballots are cast. The final one is scheduled for Feb. 16 in Saskatoon.
In the 2009 leadership race that Lingenfelter won, an NDP volunteer was charged after the RCMP received a complaint that some membership applications paid for by Lingenfelter were forged.
Ernest Morin pleaded guilty to attempting to utter forged documents and was fined $3,000.
A report commissioned by the NDP said Lingenfelter's campaign did not direct or condone the activity.