Abstract
We introduce the concept of photonic flatband resonances and demonstrate it for an array of high -index dielectric particles. We employ the multiple Mie scattering theory and demonstrate that both shortand long-range interactions between the resonators are crucial for the emerging collective resonances and their associated photonic flatbands. By examining both near- and far -field characteristics, we uncover how the flatbands emerge due to a fine tuning of resonators' radiation fields, and predict that hybridization of a flatband resonance with an electric hot spot can lead to giant values of the Purcell factor for the electric emitters.