Most optical metamaterials fabricated and studied to date employ metallic components resulting in significant losses,heat and overall low efficiencies.A new era ofmetamaterial physics is associated with all-dielectric meta-optics,which employs electric and magnetic Mie resonances of subwavelength particles with high refractive index for an optically induced magnetic response,thus underpinning a new approach to design and fabricate functional and practical metadevices.Here we review the recent developments in meta-optics and subwavelength dielectric photonics and demonstrate that the Mie resonances can play a crucial role in the realization of the unique functionalities of meta-atoms,also driving novel effects in the fields ofmetamaterials and nanophotonics.We discuss the recent research frontiers in all-dielectric meta-optics and uncover how Mie resonances can be employed for a flexible control of light with full phase and amplitude engineering,including unidirectional metadevices,highly transparent metasurfaces,non-linear nanophotonics and topological photonics.