Argelius IV was the inhabited fourth planet in the Argelius star system. This planet was located in the Beta Quadrant and was approximately 79 light years from Sol.
While serving together on the USS Stargazer in the early 24th century, Jean-Luc Picard and Jack R. Crusher once had shore leave on Argelius IV, where they met a pair of enthusiastic young women. After they were unexpectedly recalled to their ship, Picard concocted a plan to "borrow" a shuttle with which to return to the planet and dally with them. On the way back, their shuttle was almost disabled by a micrometeoroid shower. (PIC: "No Win Scenario")
This planet was only mentioned in dialogue.