Parton Distribution Functions (PDFs) are a crucial input at the LHC, their uncertainty often being the limiting factor in the accuracy of theoretical predictions. At the same time the LHC is providing us with a number of precise measurements that help in constraining PDFs. In the first part of this talk a brief overview on the state of the art of PDF determination is given. In the second part, I will present NNPDF3.0, a new global PDF determination including HERA-II deep-inelastic cross-sections, jet production from ATLAS and CMS, vector boson rapidity and transverse momentum distributions from ATLAS, CMS and LHCb, W + c data from CMS and top quark total cross sections from ATLAS and CMS. The impact of each new measurement is assessed. Results are based on LO, NLO and NNLO QCD theory and also include electroweak corrections. Phenomenological implications for the upcoming 13 TeV Run of the LHC, in particular for Higgs production cross-sections are explored.