Yang said he tested negative as recently as this weekend but received a positive result from a rapid test, according to a statement from his campaign.
"I'm experiencing mild symptoms, but am otherwise feeling well and in good spirits," he said. "I will quarantine in accordance with public health guidelines and follow the advice of my doctor."
Two weeks ago, Yang entered quarantine after a member of his campaign staff tested positive for the virus.
Yang added that he will continue to attend virtual events and would return to the campaign trail "when the time is right."
His campaign team said it has begun contact tracing to notify anyone who may have been in contact with Yang.
In December, Yang -- born in Schenectady, N.Y. --filed paperwork to run for mayor of New York City.
He previously launched a bid for president centered around a universal basic income that would provide $1,000 to Americans older than 18 every month. He joined CNN as a political analyst and in November announced he would move to Georgia to help Democratic senate candidates Jon Ossoff and Raphael Warnock win runoff races in the state.