Bottoms is expected to speak between 9 and 10 p.m. ET on Thursday, shortly before newly minted nominee Biden takes the (virtual) stage.
Thursday is the fourth and final day of the convention. Milwaukee had been preparing to host the convention that was expected to draw tens of thousands of people, but the coronavirus pandemic turned it into an online event.
Here are five things to know about Bottoms:
1. She was reportedly on Biden's running mate shortlist
House Majority Whip James Clyburn, D-S.C., an influential Black lawmaker whose endorsement propelled Biden to victory in South Carolina's primary, mentioned Bottoms as a contender for Biden's vice president to the Financial Times in early April.
In this July 17, 2019, file photo, Atlanta Mayor Keisha Lance Bottoms speaks during a Senate Democrats’ Special Committee on the Climate Crisis on Capitol Hill in Washington. (AP Photo/Andrew Harnik, File)
"There is a young lady right there in Georgia who I think would make a tremendous VP candidate, and that's the mayor of Atlanta, Keisha Lance Bottoms," Clyburn said.
Biden had said he would choose a woman for his running mate and ended up picking his former presidential primary rival Sen. Kamala Harris, D-Calif.
2. She endorsed Biden early on in the race
Bottoms endorsed Biden in June 2019, just as Harris ripped into Biden’s civil rights record for his past opposition to busing and of a time when he spoke fondly of his relationship with two segregationist senators. It would be another 10 months before even former President Barack Obama endorsed his former VP.
Bottoms also attended that first debate as the guest of Biden’s wife, Jill. She attended other debates and stood by his side even as his poll numbers slipped in early rounds of voting this year.
In this screenshot from the DNCC’s livestream of the 2020 Democratic National Convention, Democratic presidential nominee former Vice President Joe Biden and Dr. Jill Biden together gives a thank you speech with supporters during the virtual convention on August 18, 2020. (Photo by Handout/DNCC via Getty Images)
"He is a strong candidate and there have been some bumps along the way, but I think that's to be expected. Nobody ever said it would be easy," Bottoms told 11Alive News in November 2019. "When you look at the legacy that the Obama-Biden administration has in Georgia, people remember that and especially when you look at large groups of people of color as a demographic in our state then, by and large, especially our seasoned African American voters, are solidly behind Joe Biden."
3. She made impassioned speeches condemning violence, looting in the wake of George Floyd's death
In a state where nearly one-third of the population is Black, Bottoms repeatedly condemned violence and looting as protests erupted across the nation following the death of George Floyd in police custody in Minneapolis.
People carry signs as they march Monday, June 1, 2020, in Atlanta during demonstration over the death of George Floyd, who died after being restrained by Minneapolis police officers on May 25. (AP Photo/John Bazemore).
"What I see happening on the streets of Atlanta is not Atlanta. This is not a protest. This is not in the spirit of Martin Luther King, Jr.," Bottoms said at a news briefing. "This is chaos."
"A protest has purpose. When Dr. King was assassinated, we didn't do this to our city," Bottoms said. "If you want change in America, go and register to vote. … That is the change we need in this country."
4. She clashed with Gov. Brian Kemp over the state's early coronavirus reopening
Georgia was one of the earliest states to begin the reopening process on April 24, but Bottoms urged residents of her city to ignore the Republican governor's decision to reopen the economy and remain home.
"Stay home. Listen to the scientists," Bottoms told George Stephanopoulos on ABC News' "Good Morning America." "There is nothing essential about going to a bowling alley or getting a manicure in the middle of a pandemic."
Atlanta Mayor Keisha Lance Bottoms — who announced Monday she tested positive for coronavirus – feels Georgia was “too aggressive" when the state reopened from COVID-19 shutdowns. (Photo by Paras Griffin/Getty Images for Essence)
She said she hadn’t been consulted by Kemp and he hadn’t explained to her how his decision was guided by science or experts.
5. She is the daughter of 1960s R&B star Major Lance
Bottoms was born in Atlanta to R&B singer-songwriter Major Lance. She later attended Florida A&M, a historically black university in Tallahassee, before returning home to obtain her law degree from Georgia State University. She served as a judge and city council member for six years before becoming mayor in 2017.
Fox News' Morgan Phillips contributed to this report.