The Nice Summer School on Markov chains, random walks, random graphs and its applications to complex networks will be held in Nice (France) from July 8-19, 2019. One of the two courses focusses on different models of random graphs (model G(n,p), configuration model, preferential attachment model, random graph processes, ...) together with techniques in these models (switching techniques, differential equation method,...), whereas the other course will focus on concepts and techniques related to random walks and Markov chains (mixing times, hitting times, random spanning trees, cutoff phenomena, ...).