series finale

The term came into use in American television in the early 1990s, as a variation of the term season finale. Prior to that, closing episodes were originally called the "final episode" or "last episode."

series finale (plural series finales)

1. The promotional or advertisement term used to describe the final episode of a television program, usually a situation comedy or a drama.

As a common use-term, the term series finale is used to refer to a planned final episode, which includes resolution. The term last episode is used to refer to the last episode of a television program that was canceled after that episode was filmed.