This makes Ossoff, 33, the youngest Democratic senator-elect since Joe Biden in 1973.
Biden, the 78-year-old president-elect, won his first Senate seat in Delaware at the age of 30.
Ossoff is also the first millennial to be elected to the Senate.
The youngest incumbent senator had been Sen. Josh Hawley, a 41-year-old Missouri Republican.
Jon Ossoff has become the youngest Democrat to be elected as a US senator since Joe Biden in 1973.
The last time a Democratic candidate as young as Ossoff won a Senate seat was in 1973, when a 30-year-old Biden defeated Republican Sen. J. Caleb Boggs to represent Delaware.
Wins for Warnock and Ossoff mean the Democratic Party now controls both the House of Representatives and the Senate. »