Scott Reid took an early lead in the race in St. George's-Stephenville East on Tuesday, making it the fourth consecutive byelection loss for the provincial Tories.
According to Elections Newfoundland and Labrador, unofficial results indicate Reid took 2,211 votes, Wally Childs got 948 for the Tories and NDP candidate Bernice Hancock won 579 votes.
The district became vacant after Joan Shea announced in June she was quitting politics.
She was first elected in October 2003 and held various cabinet positions, including minister of education, human resources and employment, and child, youth and family services.
With the win, the Liberals now have 13 seats, the Tories 32 and the NDP have three seats.