The Central Database of Shoah Victims' Names

This database is:

an international undertaking led by Yad Vashem, from Jerusalem. It is the attempt to reconstruct the names and life stories of all the Jews who perished in the Shoah [Holocaust].

Contains about three million records, based on pages of testimony, historical documentation, and local commemoration projects. Data for the items vary, but may include date and place of birth and death, spouse's name, profession, and other details.
http://www.yadvashem.org/wps/portal/