Various embodiments of the disclosure relate to a proximity-illuminance sensor and an electronic device including the same to increase the accuracy of the illuminance sensor and addressing crosstalk issues. According to an embodiment, an electronic device comprises a transparent member, a scattering member disposed under a portion of the transparent member to scatter light incident at a designated angle from an outside of the electronic device through the transparent member, a light receiving element disposed under the portion and configured to obtain scattered light which is scattered by the scattering member from at least a part of incident light, and a control circuit configured to determine a brightness of the incident light based on, at least, the scattered light obtained through the light receiving element. The electronic device may be implemented in various manners according to embodiments of the disclosure.