News of Ossoff's projected victory, which was announced less than an hour after polls closed, rippled through the Georgia Democrats watch party in Atlanta with supporters cheering and clapping.
He began his remarks by thanking his family and voters in Georgia for their support, replying "I love you, too", in response to shouts coming from the jubilant crowd.
He returned to many of the points he made on the campaign trail, expressing his concern about the economic woes faced by everyday Americans, while attacking big pharma and corporate America and alleged corruption in the White House.
"This moment is an opening not for restoration, but for reformation," Ossoff said. "And so, amidst our celebration tonight, we must acknowledge that the underlying crisis gripping our Republic remains, and that therefore, our most vital work lies ahead."
The race was one of the first major contests projected as part of the midterms on Tuesday, which will shape the rest of Donald Trump's presidency. The outcome will determines which party - Trump's Republicans or opposition Democrats - controls Congress.
Brian Kemp, Georgia's term-limited Republican governor, was the favoured candidate to run against Ossoff, but he declined.
Political pundits suspected that Kemp had avoided running, wary of Ossoff's rising star power, with rumours swirling that the Democrat could be mulling a run for president in 2028.
Throughout his campaign, Ossoff downplayed such rumours, saying on multiple occasions that he has "zero interest" in a presidential bid.
His messaging on the campaign trail focused on the economy and voter concerns around affordability, which exit polls show was the top issue for many.