Mayor Pro Tem William Brian Yates was elected to Seat Number 3 in 2019 and re-elected in 2023. He is serving as Mayor Pro Tem in 2025. A Winter Haven native and 7th generation Floridian, Brian graduated from Winter Haven High School, attended Polk State College, and graduated from the Florida School of Banking. Brian is a Senior Vice President and the Director of Small Business Lending at Citizens Bank and Trust. He is a member and past President of the Rotary Club of Winter Haven and a past member of the Florence Villa Community Redevelopment Agency (CRA) Advisory Committee. Brian and his wife Samantha have two sons.

Brian is a board member of the Community Redevelopment Agency (CRA) Board, the Florida League of Cities (FLC) Board of Directors, and serves as the Commission liaison to:

• FLC Federal Action Strike Team (FAST)
• FLC Legislative Policy Finance and Taxation Committee 
• Main Street Winter Haven (MSWH)
• Planning Commission
• Polk Transportation Planning Organization (TPO) (Seat Number 2)
• Ridge League of Cities (RLC) (President Elect) 
• Polk County Tourist Development Council (TDC)