"The Senate provides a singular platform from which to address the issues of access to justice, economic security, health care and restoring the integrity of our nation's democracy," Abrams said in the video. "However, I am announcing today that I will not be a candidate for the United States Senate."
Abrams met with Senate Democratic leader Chuck Schumer on Monday to inform him of her plans.
A Democratic official, speaking on condition of anonymity, said Abrams will focus on her voting rights project. She has not decided whether to seek any other office at this time.
Abrams is considered a rising star in Democratic politics. A former Georgia state House minority leader, Abrams rose to national prominence last year during a closely fought gubernatorial bid. Abrams, who would have been the first African American woman ever elected governor, narrowly lost the race in the reliably red state.
She refused to concede the race amid significant controversy over the way the election was conducted -- a process overseen by her opponent, now-Gov. Brian Kemp, who was Georgia's secretary of state at the time. She eventually acknowledged defeat but has consistently said in the months following the vote that she believes it "was a stolen election."
Earlier this month, she lashed out at Kemp and called him a "cartoon villain" and an "architect of voter suppression."
Abrams has previously said it was possible she could seek her party's presidential nomination in 2020. Earlier this month, she said running for president is "probably third on the list" of her potential future bids for office, behind running for the US Senate or running for governor again in Georgia.
She made history as the first black woman to give the Democratic response to the State of the Union earlier this year. In her speech, she sharply criticized the Trump administration and Republican leadership, blaming the President for the longest government shutdown in modern US history.
Abrams, who has made voting rights her signature issue, warned during her speech that voter suppression is "real" and described protecting the right to vote as "the next battle for our democracy."
This story has been updated.