Disclosed embodiments relate to spatial and temporal merging of remote atomic operations. In one example, a system includes an RAO instruction queue stored in a memory and having entries grouped by destination cache line, each entry to enqueue an RAO instruction including an opcode, a destination identifier, and source data, optimization circuitry to receive an incoming RAO instruction, scan the RAO instruction queue to detect a matching enqueued RAO instruction identifying a same destination cache line as the incoming RAO instruction, the optimization circuitry further to, responsive to no matching enqueued RAO instruction being detected, enqueue the incoming RAO instruction; and, responsive to a matching enqueued RAO instruction being detected, determine whether the incoming and matching RAO instructions have a same opcode to non-overlapping cache line elements, and, if so, spatially combine the incoming and matching RAO instructions by enqueuing both RAO instructions in a same group of cache line queue entries at different offsets.