The LHC Run III will be a crucial run for the two LHC forward experiments: LHCf and FASER. In particular, Run III will be the last run where the LHCf detector can operate, and the first run of the new FASER project. The LHCf experiment is dedicated to precise measurements of forward production, necessary to tune hadronic interaction models employed in cosmic-ray physics. In Run III, the experiment will accomplish two fundamental goals: operating in p-p collisions at $\sqrt{s} = $ 14 TeV, it will acquire a statistics that is ten times larger respect to Run II, in order to have precise measurements of $\pi^{0}$ production; operating in high energy p-O and O-O collisions, it will measure forward production in a configuration that is very similar to the first interaction of an Ultra High Energy Cosmic Ray with an atmospheric nucleus. The FASER experiment is dedicated to the search of new weakly-interacting light particles thanks to a forward detector with proper shielding from Standard Model background. In Run III, it will be able to search for new particles with a good sensitivity, which can be strongly improved after an upgrade before Run IV. In addition, thanks to the dedicated FASER$\nu$ detector, it will measure neutrino production at a collider for the first time. In this contribution, we discuss the main results expected from the LHCf and FASER experiments in Run III, highlighting their fundamental contribution in research fields that are not accessible to the four large LHC experiments.