Schwielochsee (Lower Sorbian: Gójacki Jazor) is a municipality in the district of Dahme-Spreewald in Brandenburg in Germany formed of 10 small villages. It is located at the southern shores of the lake Schwielochsee.

On 26 October 2003, the municipality of Schwielochsee was formed by merging six municipalities. These were Goyatz-Guhlen, Jessern, Lamsfeld-Groß Liebitz, Mochow, Ressen-Zaue and Speichrow.

From 1815 to 1947, the constituent localities of Schwielochsee were part of the Prussian Province of Brandenburg, from 1947 to 1952 of the State of Brandenburg, from 1952 to 1990 partially (Goyatz-Guhlen, Jessern, Lamsfeld-Groß Liebitz, Mochow and Ressen-Zaue) of the Bezirk Cottbus and partially (Speichrow) of the Bezirk Frankfurt of East Germany. Since 1990, they have again been part of Brandenburg, since 2003 united as the municipality of Schwielochsee.

Schwielochsee: Population development
within the current boundaries (2017)

Year Pop. ±% p.a. 1875 2,517 —     1890 2,327 −0.52% 1910 1,985 −0.79% 1925 1,950 −0.12% 1933 1,928 −0.14% 1939 1,929 +0.01% 1946 2,790 +5.41% 1950 2,538 −2.34% 1964 1,785 −2.48% 1971 1,698 −0.71% 1981 1,509 −1.17% 1985 1,491 −0.30% 1989 1,501 +0.17% 1990 1,500 −0.07%

Year Pop. ±% p.a. 1991 1,506 +0.40% 1992 1,548 +2.79% 1993 1,523 −1.61% 1994 1,522 −0.07% 1995 1,549 +1.77% 1996 1,572 +1.48% 1997 1,588 +1.02% 1998 1,643 +3.46% 1999 1,700 +3.47% 2000 1,706 +0.35% 2001 1,741 +2.05% 2002 1,734 −0.40% 2003 1,699 −2.02% 2004 1,693 −0.35%

Year Pop. ±% p.a. 2005 1,702 +0.53% 2006 1,668 −2.00% 2007 1,666 −0.12% 2008 1,633 −1.98% 2009 1,628 −0.31% 2010 1,613 −0.92% 2011 1,600 −0.81% 2012 1,561 −2.44% 2013 1,556 −0.32% 2014 1,523 −2.12% 2015 1,499 −1.58% 2016 1,490 −0.60% 2017 1,488 −0.13%