The interplay between dark matter and black holes remains largely unexplored. Dark matter can in principle be made of black holes, as long as these are primordial, i.e. they are formed in the very early universe. Dark matter can also accumulate around black holes, and modify the rich phenomenology exhibited by these objects. After an overview of the status of dark matter searches, I will discuss the prospects for detecting primordial black holes or robustly ruling them out as dark matter candidates. I will then discuss the prospects for characterizing and identifying dark matter using gravitational waves, covering a wide range of dark matter candidate types and signals.