An image encoding/decoding method and apparatus are provided. An image decoding method according to the present disclosure is performed by an image decoding apparatus. The image decoding method comprises determining whether bi-directional optical flow (BDOF) or prediction refinement with optical flow (PROF) applies to a current block, based on BDOF or PROF applying to the current block, fetching a prediction sample of the current block from a reference picture of the current block based on motion information of the current block, and deriving a refined prediction sample for the current block, by applying BDOF or PROF to the current block based on the fetched prediction sample.