Modularity is a particularly powerful symmetry with many applications in theoretical physics and mathematics, in particular quantum field theory and string theory. Resurgence is a general framework for advanced asymptotics which effectively unifies perturbative and non-perturbative physics via an intricate network of algebraic relations known as Ecalle’s bridge equations. Modularity and resurgence overlap strongly in the goal of exploring non-perturbative completions of perturbative data, leading to profound new insights into the connection between weak coupling and strong coupling, and in the study of dualities, black holes and quantum gravity. The goal of this GGI Workshop is to bring together experts from these two frontier areas in theoretical and mathematical physics to foster further interaction between different scientific communities and to develop novel strategies to address truly significant problems.