  The remarkable progress made in infrared (IR) astronomical instruments over
the last 10-15 years has radically changed our vision of the extragalactic IR
sky, and overall understanding of galaxy evolution. In particular, this has
been the case for the study of active galactic nuclei (AGN), for which IR
observations provide a wealth of complementary information that cannot be
derived from data in other wavelength regimes. In this review, I summarize the
unique contribution that IR astronomy has recently made to our understanding of
AGN and their role in galaxy evolution, including both physical studies of AGN
at IR wavelengths, and the search for AGN among IR galaxies in general.
Finally, I identify and discuss key open issues that it should be possible to
address with forthcoming IR telescopes.
