Mayor Undersee lived with his wife and daughter, Madge Undersee. He and his family died in the District 12 bombing. Maysilee Donner, who died in the 50th Hunger Games, was his sister-in-law and his wife's twin sister.
Mayor Undersee was described as being a tall, balding man.
- Mayor Undersee had a fondness of strawberries, which Katniss Everdeen often sold to him.