System J-25 was a planetary system that had at least six planets. It was located more than 7,000 light years from Starbase 185 of the United Federation of Planets, the closest starbase in the 24th century.
In the 24th century, the Borg had a presence in the system. A Borg cube scout detected the Federation starship USS Enterprise-D when it was transported to this system by Q in 2365. Shortly after, the Enterprise-D made first contact.