Did Albert Speer know about the Holocaust

[Lumine]

Yes. Gitta Sereny has what I think is the most comprehensive biography of Speer (which she wrote by speaking with him across several years), and while Speer was always elusive about the subject her conclusion was that he did know. She does note that Speer probably repressed the knowledge and possibly wanted to believe he did not know, but the evidence points he was there in least on occasion in which the matter was discussed during the war.

Important (due to the collective admission of guilt) and "brilliant" as his defence was in Nuremberg (escaping death while his subordinate Sauckel was sentenced to death), he knew about it.