Romney, 74, "is currently asymptomatic and will be isolating and working remotely for the recommended period of time," according to the statement.
Romney's wife has tested negative and the couple have been fully vaccinated and boosted against the virus, it said.
The senator from Utah is the 2012 Republican presidential nominee.
Several dozen U.S. lawmakers have tested positive for COVID-19 since last summer.
The current 7-day moving average of daily new cases in the United States is still as high as nearly 600,000, according to data from the Centers for Disease Control and Prevention.
A total of 72,874,041 COVID-19 cases have been reported nationwide as of Jan. 26, 2022.
Anthony Fauci, U.S. top infectious disease specialist, has voiced confidence that most states will see COVID-19 cases peak in mid-February.