Vicki Mowat is seeking NDP nomination for the Saskatoon Fairview MLA seat.
The move comes after Jennifer Campeau stepped down from her MLA position on Sunday to take a job with Rio Tinto in B.C.
The NDP will announce their official candidate on July 24.
Mowat, an administrator in the Aboriginal Affairs department at the University of Saskatchewan and former Canadian Forces Reserves captain, ran against Campeau in the 2016 provincial election.
Campeau won the Saskatoon Fairview seat by 182 more votes than Mowat.
It was another close race in 2011, when Campeau won by 247 votes.
“This constituency we’re talking about is tough,” Premier Brad Wall said during Campeau’s announcement of stepping down.
“You know, we’re pretty realistic about that. It’s going to be very difficult, but we’re going to do what Jennifer did, which was earn the support of people at the doorsteps of the constituency when we call a byelection.”
A byelection must be held within six months to fill the vacant seat.
--- CORRECTION: An earlier version of this story stated Vicki Mowat was the NDP candidate for the Saskatoon Fairview MLA seat. She is in fact seeking the NDP candidacy. CTV regrets the error.