The Astrophysics and Cosmology Group includes 10 staff members, 5 postdocs and 25 Ph.D. students. We address fundamental questions in the very broad fields of astrophysics, cosmology and fundamental physics. Our research interests include: early universe physics, analysis and interpretation of cosmic microwave background data, large-scale structures, galaxy cluster physics, galaxy formation and evolution, dark energy and dark matter, galactic and extragalactic black holes, stellar structure and evolution, high-energy and multimessenger astrophysics, gravitational waves. In the Astrophysics and Cosmology Ph.D. curriculum our students are trained to become junior scientists via lecture courses followed by research work, participation to international collaborations, conferences and observational projects/networks. Researchers, postdocs and students working at SISSA can also take advantage of the rich environment of scientific institutions present in the Trieste area, such as the International Centre for Theoretical Physics (ICTP), the Istituto Nazionale di Fisica Nucleare (INFN), the Istituto Nazionale di Astrofisica (INAF-Astronomical Observatory of Trieste), and the Institute for Fundamental Physics of the Universe (IFPU).