WS-ReliableMessaging describes a protocol that allows messages to be delivered reliably between distributed applications in the presence of software component, system, or network failures.

The original specification was written by BEA Systems, Microsoft, IBM, and Tibco and in March, 2003 and subsequently refined over the next two years. The February, 2005 version was submitted to the OASIS Web Services Reliable Exchange (WS-RX) Technical Committee in June of that year. The resulting WS-ReliableMessaging 1.1 was approved as an OASIS Standard on June 14th, 2007.

Prior to WS-ReliableMessaging, OASIS produced a competing standard (WS-Reliability) that was supported by a coalition of vendors; namely Fujitsu, Hitachi, NEC, Oracle Corporation, Progress Software, and Sun Microsystems. Most of these vendors now also support the WS-ReliableMessaging specification.