Inflation is the paradigm to understand the emergence of the primordial perturbations that seeded the growth of structure in the universe, based on the magnification of quantum fluctuations from a very early epoch. String Theory is the only consistent proposal for an ultraviolet completion of General Relativity, and more generally for a theoretical framework able to describe all the known fundamental interactions in Nature and the quantum gravity regime. The aim of the workshop is, on the one hand, to discuss the common ground between Cosmology, String Theory and Supergravity, looking for theoretical predictions on the fundamental observables tested in experiments. On the other hand, experimental data are today reaching an unprecedented level of accuracy. It is thus essential to analyze how recent experiments like Planck and Ligo-Virgo can provide data in order to constrain inflationary models, including those coming from String Theory. The Workshop is part of the S.T.a.I. (String Theory and Inflation) Program of the Physics Department of the University of Rome Tor Vergata.