In the seven-layer OSI model of computer networking, the logical link control (LLC) data communication protocol layer is the upper sublayer of the data link layer, which is itself layer 2. The LLC sublayer provides multiplexing mechanisms that make it possible for several network protocols (IP, IPX, Decnet and Appletalk) to coexist within a multipoint network and to be transported over the same network medium. It can also provide flow control and automatic repeat request (ARQ) error management mechanisms.

The LLC sublayer acts as an interface between the media access control (MAC) sublayer and the network layer.