Turner received 903 of the total 1,502 votes cast, giving him 60.1 percent of the vote, according to unofficial election results. His opponent, Brian Laurens, earned 599 votes.
“I am just so proud of my team right now,” Turner said Tuesday night.
Campaign organizers Tori Wester and Robert Lee organized more than 50 campaign volunteers, Turner said.
“I am speechless about the amount of support we had help us get the word out about this race,” he said. “I’m excited for the opportunity to serve, and I want to enter into this with a servant’s heart.”
Turner added that he will have “a steep hill to climb” coming into the legislative session late, but said he’s been following legislative activity since the session began.
“I should be able to hit the ground running. I’m looking forward to getting down to the Gold Dome and serving the people of the 21st District,” he said.
Turner called ethics reform his “cornerstone issue” during the campaign.
Laurens was not available for comment Tuesday night.
Turnout for the runoff was low, with 4.59 percent of the district’s 32,860 registered voters casting ballots.
Turner and Laurens found themselves in the runoff for the District 21 seat after garnering 46 percent and 30 percent of the vote, respectively, in a four-way special election in January.
The House District 21 seat opened in December after former Rep. Sean Jerguson resigned the seat to run in a special election for state Senate District 21. Brandon Beach (R-Alpharetta) won the race for the Senate seat formerly held by Chip Rogers.