Havelsee (German pronunciation: [ˈhaːfl̩ˌzeː] ) is a town in the Potsdam-Mittelmark district, in Brandenburg, Germany. It is situated on the river Havel, 12 km northwest of Brandenburg.

The Pritzerbe Ferry, a vehicular cable ferry, crosses the Havel between Havelsee and Kützkow.

The mayor of Havelsee since 2003 is Günther Noack, he was reelected in 2014 with 83,4 % of the votes.

Over 80% of the area of the borough of Havelsee is covered by overlapping protected areas of various types. These include the natural monument of Weißes Fenn Marzahne as well as 3 nature reserves and 4 SACs.

• Lothar Kreyssig (1898-1986), magistrate in Brandenburg an der Havel, a member of the Confessing Church, euthanasia opponents and founder of Action Reconciliation Service for Peace, 1937-1971 residing in the Bruderhof at Hohenferchesar
• Walter Kuntze (1883-1960), General of the Wehrmacht

Havelsee: Population development
within the current boundaries (2013)

Year Pop. ±% p.a. 1875 4,164 —     1890 4,351 +0.29% 1910 3,992 −0.43% 1925 3,857 −0.23% 1933 3,960 +0.33% 1939 4,419 +1.84% 1946 5,117 +2.12% 1950 5,093 −0.12% 1964 3,953 −1.79% 1971 3,770 −0.67% 1981 3,170 −1.72% 1985 3,076 −0.75% 1989 2,923 −1.27% 1990 2,858 −2.22% 1991 2,775 −2.90% 1992 2,774 −0.04% 1993 2,810 +1.30% 1994 2,907 +3.45% 1995 3,125 +7.50% 1996 3,392 +8.54%

Year Pop. ±% p.a. 1997 3,546 +4.54% 1998 3,670 +3.50% 1999 3,709 +1.06% 2000 3,737 +0.75% 2001 3,712 −0.67% 2002 3,681 −0.84% 2003 3,613 −1.85% 2004 3,562 −1.41% 2005 3,523 −1.09% 2006 3,516 −0.20% 2007 3,490 −0.74% 2008 3,512 +0.63% 2009 3,493 −0.54% 2010 3,503 +0.29% 2011 3,431 −2.06% 2012 3,349 −2.39% 2013 3,275 −2.21% 2014 3,268 −0.21% 2015 3,234 −1.04% 2016 3,244 +0.31%

• Potsdamer Brandenburger Havelseen, Tourist information