F5, Inc. is an American technology company specializing in application security, multi-cloud management, online fraud prevention, application delivery networking (ADN), application availability and performance, and network security, access, and authorization.

F5 is headquartered in Seattle, Washington in F5 Tower, with an additional 75 offices in 43 countries focusing on account management, global services support, product development, manufacturing, software engineering, and administrative jobs. Notable office locations include Spokane, Washington; New York, New York; Boulder, Colorado; London, England; San Jose, California; and San Francisco, California.

F5 originally offered application delivery controller (ADC) technology, but has since expanded into application layer, automation, multi-cloud, and security services. As ransomware, data leaks, DDoS, and other attacks on businesses of all sizes are arising, companies such as F5 have continued to reinvent themselves. While the majority of F5's revenue continues to be attributed to its hardware products, such as the BIG-IP iSeries systems, the company has begun to offer additional modules on its proprietary operating system, TMOS (Traffic Management Operating System). These modules include Local Traffic Manager (LTM), Advanced Web Application Firewall (AWAF), DNS (previously named GTM), and Access Policy Manager (APM). These offer organizations that run BIG-IP systems the ability to deploy load balancing, Layer 7 application firewalls, single sign-on (for Azure AD, Active Directory, LDAP, and Okta), as well as enterprise-level VPNs. While the BIG-IP was traditionally a hardware product, F5 now offers it as a virtual machine, which it has branded as the BIG-IP Virtual Edition. The BIG-IP Virtual Edition is cloud-agnostic and can be deployed on-premises in a public and/or hybrid cloud environment.