There is much speculation about the chemistry occurring in astronomical environments, but without observation of such environments, speculation is without foundation. Observational astrochemistry is the foundation on which astrochemistry is built. It offers us a window into a world that would otherwise be beyond our reach. Chemical spectroscopy helps identify chemical species and probe their environments; gas-phase, surface, solid-state and photochemically-induced chemical processes drive the evolution of our galaxy and others; chemical evolution controls the formation of stars and planets; chemistry is the forerunner that brings us to the edge of biology and of life itself. This window to our universe is being opened more widely as a revolution in the observational capabilities available to astronomers is expected to continue through the 2020s and beyond. Join internationally leading experimental and theoretical scientists from across the fields of astronomy, chemistry and physics to explore and exchange ideas about our chemical understanding of the universe. The topics are organised into the following sections: Observational astrochemistry in the age of ALMA, NOEMA, JWST and beyond Laboratory astrochemistry of the gas phase Laboratory astrochemistry of and on dust and ices Computational astrochemistry