The behaviour of physical fundamental constants is an effective way to probe fundamental physics and cosmological models. The fine-structure constant α and the proton-to-electron mass ratio µ can be studied with a range of physical observables across the Universe, including spectra of the more distant quasars, Cosmic Microwave Background and Primordial Nucleosynthesis. A connection between the variation of fundamental parameters and the nature of dark energy could be tested. We will bring together the most active researchers in this area to discuss the latest developments. The conference proceedings will be possibly published in the Memorie della Società Astronomica Italiana.