"S.R. 819" is the ninth episode of the sixth season of the science fiction television series The X-Files. It premiered on the Fox network on January 17, 1999 in the United States. The episode was written by John Shiban, and directed by Daniel Sackheim. The episode helps to explore the series' overarching mythology. "S.R. 819" earned a Nielsen household rating of 9.1, being watched by 15.7 million people in its initial broadcast.