Gallagher is from the Yorkton area and has been a constituency organizer and party president.
The Liberals say he'll be a steady hand as they work towards reconnecting with people and planning for the upcoming leadership race.
Former leader Ryan Bater (BHATE-er) quit in January after almost three years at the party's helm.
The move came after the Liberals failed to win a seat in last fall's provincial election and Bater finished third in his home constituency of The Battlefords.
No one has been elected to the legislature under the Liberal name since 1999.
Note to readers: This is a corrected story. A previous version had Battlefords.