Quinn, a journalist and former mayor of Leesburg, had secured the most votes in the four-way November race, receiving about 41.6% of the nearly 9,300 ballots cast. Yearta secured 34.3% of votes cast last month.
A runoff was required since neither candidate won more than 50% of the votes cast in the special election.
Rynders announced his retirement in September, citing health reasons and plans to move to St. Simons Island.
Yearta will represent voters in House District 152 in Lee, Sumter and Worth counties.
> More Tuesday election results from the AJC