In this talk, I review the first-principles calculations of hadron-hadron interactions from lattice QCD. I introduce a theoretical framework, HAL QCD method, where it is shown that the notion of potential can be rigorously introduced/calculated as a representation of the S-matrix of QCD. Recent numerical results are presented, in particular, for hyperon forces obtained near the physical point. The physical implications for exotic dibaryons, hyper-nuclei, equation of state of high dense matter and the structure of neutron stars are also discussed and future prospects will be given.