In telecommunications, interconnection is the physical linking of a carrier's network with equipment or facilities not belonging to that network. The term may refer to a connection between a carrier's facilities and the equipment belonging to its customer, or to a connection between two (or more) carriers.

In United States regulatory law, interconnection is specifically defined (47 C.F.R. 51.5) as "the linking of two networks for the mutual exchange of traffic."

One of the primary tools used by regulators to introduce competition in telecommunications markets has been to impose interconnection requirements on dominant carriers. The FCC's Carterfone decision in 1968 required the Bell System companies to permit interconnection by radio-telephone operators, and was the first in a series of landmark cases that led to the transformation of the long distance telephone industry from a monopoly to a competitive business.