Oracle Fusion Middleware (FMW, also known as Fusion Middleware) consists of several software products from Oracle Corporation. FMW spans multiple services, including Java EE and developer tools, integration services, business intelligence, collaboration, and content management. FMW depends on open standards such as BPEL, SOAP, XML and JMS.

Oracle Fusion Middleware provides software for the development, deployment, and management of service-oriented architecture (SOA). It includes what Oracle calls "hot-pluggable" architecture, designed to facilitate integration with existing applications and systems from other software vendors such as IBM, Microsoft, and SAP AG.^{[citation needed]}

Many of the products included under the FMW banner do not themselves qualify as middleware products: "Fusion Middleware" essentially represents a re-branding of many of Oracle products outside of Oracle's core database and applications-software offerings—compare Oracle Fusion.

Oracle acquired many of its FMW products via acquisitions. This includes products from BEA Systems and Stellent.

In order to provide standards-based software to assist with business process automation, HP has incorporated FMW into its "service-oriented architecture (SOA) portfolio".

Oracle leveraged its Configurable Network Computing (CNC) technology acquired from its PeopleSoft/JD Edwards 2005 purchase.

Oracle Fusion Applications, based on Oracle Fusion Middleware, were finally released in September 2010.

According to Oracle, as of 2013, over 120,000 customers were using Fusion Middleware. This includes over 35 of the world's 50 largest companies and more than 750 of the BusinessWeek Global 1000, with FMW also supported by 7,500 partners.