In computing, sendfile is a command which can be found in a number of contexts relating to data transmission:

• Sendfile (Unix), a push-based asynchronous file transfer, regardless of whether local or remote, using the Simple Asynchronous File Transfer (SAFT), an Internet protocol bound to TCP port 487^[1]
• Sendfile (IBM VM), a command to transfer a file asynchronously from one VM/CMS user to another, regardless of whether local or remote
• Sendfile (system call), a system call.^[2][3]
• As a command within an Instant messaging application.