This has been talked about for pretty much the entire run of the show, with the speculation only intensifying with each passing year. The biggest indicator is the opening credits sequence, which depicts a man falling - or, perhaps, jumping - from a tall building to a certain demise. Sure, it could all just be a metaphor for life and falling down, hitting rock bottom etc, but wheres the fun in that? No, this definitely shows that Don is going to die. If the credits werent enough, the show is littered with apparent references to death, in particular season 6 - in the opener alone hes seen talking to a woman about her dead husband, then reading Dantes Inferno, and the episode is called The Doorway. It all fits, right?! Unlikely, however, is the idea of Don jumping to his death from the offices of Sterling-Cooper-Draper-Pryce. It is much more likely that his years of excessive drinking, smoking and sex catch up with him.