The mandate will go into effect Oct. 24 at 12:01 a.m. and will extend through Oct. 30, which is when Gov. Bill Lee's executive order that allows counties to mandate mask expires.
"Since early summer we've worked together as a community to bring down these trends; however, today we find ourselves at a crossroad, and we need to take new action to help ensure that we are headed down the right path again."
Additionally, Anderson said Lee's executive order is expected to be extended through the end of the year, which Anderson said would allow him to extend Williamson County's mask mandate through the end of the year as well.
"Although the new executive order has not officially been granted beyond Oct. 30, when the executive order is reissued, it is my intent to also extend the mask mandate for Williamson County through the end of the calendar year," Anderson said.
Williamson County's previous mask mandate expired Aug. 29.
Exemptions from the previous county mask mandate are expected to apply, including that children ages 12 and under are exempt unless they are on school property.
"It's unfortunate that our state is continuing to see a rise in COVID-19 and hospitalizations," Anderson said. "If these trends continue, we could experience bed capacity issues in certain parts of the state as well as in our own county."
Active coronavirus cases have been steadily rising in the past weeks, peaking at 743 cases on Oct. 19, according to data from the Tennessee Department of Health.
Rogers said the mandate has received support from all city mayors in the county, with the exception of Spring Hill Mayor Rick Graham.
"The first thing I would do is applaud Mayor Anderson on this move to protect the health of our community by issuing this mask mandate," Franklin Mayor Ken Moore said. "This is an important step to protect the health of our community particularly the elderly and immunosuppressed, but also an opportunity to continue to protect our first responders, our health care professionals and folks that are on the front lines in health care."
This story is developing and will be updated.