The alleged drunk driver was on the officer's lawn.
RCMP say the constable was relaxing at his home in Yorkton on Tuesday night when he heard a noise outside and found a station wagon in his yard.
Police say the car was stuck in the snow and the motorist was trying to drive it out of a snow bank.
The off-duty constable, who is a qualified breath test technician, placed the man under arrest and detained him until on-duty officers arrived.
RCMP say the suspect's blood alcohol level was more than twice the legal limit and charges are pending.