La Cygne is a city in Linn County, Kansas, United States, and situated along the Marais des Cygnes River. As of the 2020 census, the popul…La Cygne is a city in Linn County, Kansas, United States, and situated along the Marais des Cygnes River. As of the 2020 census, the population of the city was 1,050. The city is named after the Marais des Cygnes River which is a French translation of an Osage appellation meaning "marsh of the swans".