The axion represents a plausible solution to the strong CP problem, while supersymmetry remains a leading candidate in addressing the hierarchy problem of the Standard Model. Marrying the axion with supersymmetry results in a very rich and interesting phenomenology. In my talk I first review how to build the minimal supersymmetric axion model, then I introduce a more interesting R-parity violating extension of the model and discuss various cosmological aspects, related to the axion and its superpartners, and possible experimental signatures.