This class is an introduction to the modern extragalactic astronomy and cosmology, i.e., the part of astrophysics that deals with the structure and evolution of the universe as a whole, and its major constituents: dark matter, dark energy, galaxies, quasars, large-scale structure, and intergalactic gas. It will cover the subjects including: relativistic cosmological models and their parameters, extragalactic distance scale, cosmological tests, composition of the universe, dark matter, and dark energy; the hot big bang, cosmic nucleosynthesis, recombination, and cosmic microwave background; formation and evolution of structure in the universe; galaxy clusters, large-scale structure and its evolution; galaxies, their properties and fundamental correlations; formation and evolution of galaxies; star formation history of the universe; quasars and other active galactic nuclei, and their evolution; structure and evolution of the intergalactic medium; diffuse extragalactic backgrounds; the first stars, galaxies, and the reionization era.