Thao, whose family is from Laos, was sworn in by California Attorney General Rob Bonta.
The theme of her speech was unity, calling on Oaklanders to join her and pledging to earn the trust of residents who voted for other candidates.
Telling guests, "We are one team Oakland," Thao said she believes the city’s best days are ahead.
One of 10 children born to immigrant parents, Thao was valedictorian of Merritt College and is a graduate of University of California at Berkeley. She is a survivor of domestic violence.
She said she knows what it is like to face great odds and to overcome those obstacles.
Before her election in November, she was a city council member and council president pro tem.
Thao is the city's 51st mayor and its youngest in more than 75 years.
She said her administration will double down on violence prevention strategies that work, like the Ceasefire program to ease conflicts, lower the amount of guns on the streets and "restore hope."
She pledged to fill the Police Department with experienced, diverse, homegrown officers. She said she wants to address the root causes of violence by creating strong-paying jobs and educational opportunities.
