Untersee () may refer to:
Lakes or lake sections Lake Untersee, Antarctica Untersee (Lake Constance), the smaller, lower section of Lake Constance The lower, larger part of Lake Zurich is sometimes called or
People Franz Joseph Untersee, a Swiss-American architect Joel Untersee, a Swiss football player
See also Obersee (disambiguation) Unterseen, a town in the canton of Bern, Switzerland , anglicized to U-boat