Dietmar Gerhard Bartsch (born 31 March 1958) is a German politician, former Federal Whip (Bundesgeschäftsführer) of the Party of Democratic Socialism (1997–2002, 2005–2007) and The Left (2007–2010) and member of the Bundestag.
He is married and has two children.
Since October 2015, Bartsch has served as the co-leader of Die Linke's parliamentary group, a position he holds with Sahra Wagenknecht.
Bartsch represents the moderate, reformist wing of the party.