The Argus sector was a region of space.

In 2370, the USS Enterprise-D was originally assigned to this sector, but Admiral Chekote allowed the Enterprise to postpone its mission there and search for a band of mercenaries which had apparently murdered Captain Picard. (TNG: "Gambit, Part I")

This sector was only mentioned in dialogue.
According to, this sector might have been named for the star Argus.
The Star Trek Encyclopedia (4th ed., vol. 1, p. 44) located the Argus sector in Federation space.