Recent advances in quantum dots (QDs) for classical and non-classical light sources are presented. We have established metal organic chemical vapor deposition (MOCVD) technology for InAs-based Q D lasers at 1.3 \mm and achieved ultralow threshold in Q D lasers with photonic crystal (PhC) nanocavity. In addition, single photon emitters at 1.55 \mum, GaN-based single photon sources operating at 200 K, and high- PhC nanocavity have been demonstrated.