Proton-proton collisions at the LHC produce an immense flux of high-energy (TeV scale) neutrinos along the beam (forward) direction. The breakthrough observation of LHC neutrinos by FASER in March 2023 heralds a new era in particle physics. In this talk I discuss the unprecedented reach of current (FASER, SND@LHC) and future (FASER2, AdvSND, FLArE) forward LHC neutrino experiments for studies of QCD and SM physics. I demonstrate that these experiments extend the LHC with an effective Neutrino-Ion Collider, enabling novel opportunities to pin down hadronic structure and validate models of neutrino scattering in uncharted regions. Specifically, I demonstrate that neutrino DIS at the LHC constraints the sea quark content of the proton, in particular strangeness, that measuring forward neutrino fluxes opens a window to the gluon content of the proton in regions outside the coverage of any other laboratory experiment, where new QCD phenomena such as gluon recombination may be detectable, and that forward LHC neutrino experiments provide unique inputs to high-energy astroparticle physics at IceCube, KM3NET, and AUGER.