Kreuzlingen is a municipality located in the district of Kreuzlingen within the canton of Thurgau in north-eastern Switzerland. It serves as the seat of its namesake district and holds the position of the second-largest city in the canton, following Frauenfeld. The municipality has a population of approximately 22,000 residents.
The city is situated on Lake Constance and forms part of a large conurbation that extends across the border into Germany to include the adjoining city of Konstanz. This combined urban area represents the largest conurbation on Lake Constance, with a total population reaching nearly 120,000 people.