The communications section was a department aboard the USS Enterprise.
In 2266, Lieutenant Kevin Riley was assigned to this section, having been transferred there from the engineering department. Captain James T. Kirk transferred him back to engineering upon learning that he was one of the survivors of the Tarsus IV massacre, in an effort to protect him. (TOS: "The Conscience of the King")
In the final revised draft script of "The Conscience of the King", the on-screen reference to this "communications section" was instead to the Enterprise's "communications department".