An “RDMA-Based Memory Allocator” applies remote direct memory access (RDMA) messaging to provide fast lock-free memory allocations and de-allocations for shared memory distributed across multiple servers in an RDMA-based network. Alternately, in various implementations, the RDMA-Based Memory Allocator combines RDMA messaging and remote procedure call (RPC) requests to provide fast lock-free memory allocations and de-allocations for shared memory distributed across multiple servers in an RDMA-based network. In either case, any of the networked servers can act as either or both a client for requesting (or releasing) memory allocations and a host for hosting a portion of the distributed memory. Further, any server (including the requesting client) may act as the host for the distributed memory being allocated or de-allocated by any client via RDMA messaging. Advantageously, being lock-free improves overall performance of memory access between networked computers by reducing overall system latency.