Modular forms have been one of the central topics in number theory for more a century and they continue to experience a wide range of applications throughout mathematics nowadays. Different incarnations of modularity, known as quasi-modular forms, quantum modular forms, Jacobi forms and Siegel modular forms regularly show up in physics topics such as mirror symmetry, topological quantum field theory, Gromov-Witten invariants, conformal field theory, Calabi-Yau manifolds. The principal goal of the proposed conference is to assess the role of various modular forms in recent developments in number theory, geometry and string theory.