Katja Thater (German pronunciation: [ˈkatja ˈtaːtɐ]; born 14 July 1966 in Hamburg) is a German professional poker player and horse breeder. She is married to another poker professional, Jan von Halle. Her popularity in Germany comes from the wide coverage on local television of her participation in the Poker Nations Cup and . Before becoming a professional poker player, Thater was the director of an event and marketing company in Hamburg and competed in dressage tournaments at horse shows. She continues competing in her spare time.