Devices, systems and methods for widefield three-dimensional (3D) microscopy with a quantum entanglement light source are described. An example method includes generating a first set of photons and a second set of photons, wherein each of the photons in the first set is quantum entangled with a corresponding photon in the second set, directing the second set of photons toward a sample and simultaneously directing the first set of photons toward a first two-dimensional (2D) detector, detecting, from the sample, a plurality of photons at a second 2D detector, analyzing detections from the first and second 2D detectors to determine coincidence information, and determining one or more characteristics associated with at least a three-dimensional (3D) section of the sample based on collective detections at the first and the second 2D detectors.