Through previously undiscovered private letters, photos and diaries that were found in the Himmler family house in 1945, the "The Decent One" exposes a unique and at times uncomfortable access to the life and mind of the merciless "Architect of the Final Solution" Heinrich Himmler.
| Actor | Role |
|---|---|
 Heinrich HimmlerSelf (archive footage) | Self (archive footage) |
 Tobias MorettiHeinrich Himmler (voice) | Heinrich Himmler (voice) |
 Sophie RoisMarga Himmler (voice) | Marga Himmler (voice) |
 Lotte LedlHedwig Potthast (voice) | Hedwig Potthast (voice) |
 Gudrun HimmlerNot listed | Not listed |
 Antonia MorettiGudrun Himmler (voice) | Gudrun Himmler (voice) |
 Florentin GrollGehbard Himmler (voice) | Gehbard Himmler (voice) |
 Pauline KnofAnna Himmler (voice) | Anna Himmler (voice) |
| LLenz MorettiYoung Heinrich Himmler (voice) | Young Heinrich Himmler (voice) |
 Hermann GöringSelf (archive footage) | Self (archive footage) |
| RRudolf GorslebenNot listed | Not listed |
| MMargarethe HimmlerNot listed | Not listed |
 Ernst RöhmSelf (archive footage) | Self (archive footage) |