Jaensch is a surname. Notable people with the surname include:
Chelsea Jaensch (born 1985), Australian athlete specialising in the long jump Dean Jaensch (born 1936), Australian political scientist and a retired Professor of Political and International Studies George Jaensch (1872–1958), Australian Overland Telegraph operator and post master Matthew Jaensch (born 1989), Australian rules football player Roger Jaensch (born 1971), Australian politician Christian Jaensch (born 1796), Immigrant from Kay, Brandenburg, Prussia. One of the original trustees of Hahndorf