Nigala IV was the fourth planet of the Nigala system, and was the location of a Federation base-station in the mid-2360s.
In 2366, Nigala IV was the destination of the USS Enterprise-D following its humanitarian mission to Bre'el IV. (TNG: "Deja Q")
According to the Star Trek: Star Charts ("United Federation of Planets III"), Nigala IV was the name for an outpost or space station in the Alpha Quadrant.