The following post provides a reasonably complete listing of German (meaning in Germany) Genealogical Societies and Groups. As I get and add new sites, this list will be ‘automagically’ updated.
Note: Given the post- WW2 forcible expulsion of millions of Eastern Germans from former Eastern German lands and provinces, you may wish to examine Polish Genealogical Groups & Websites for pre- 1947 German forebears (N.B.: ManyRoads does not offer information on other Eastern Slavic or Bltic Societies)
Should you know of additional organizations we ought to included in our compendium, please contact me with the particulars and I will add them.