Technologies for fine-grained completion tracking of memory buffer accesses include a compute device. The compute device is to establish multiple counter pairs for a memory buffer. Each counter pair includes a locally managed offset and a completion counter. The compute device is also to receive a request from a remote compute device to access the memory buffer, assign one of the counter pairs to the request, advance the locally managed offset of the assigned counter pair by the amount of data to be read or written, and advance the completion counter of the assigned counter pair as the data is read from or written to the memory buffer. Other embodiments are also described and claimed.