Valt Minor was an inhabited planet in the Valt system, in the Beta Quadrant. This planet was named in honor of Valt, and was the homeworld of the Valtese and historically, the former homeworld of the Kriosians.

The planet was the site of the Temple of Akadar, the historic seat of power for the empire ruled by Valt and Krios, the two brothers who were the progenitors of the Valtese and Kriosian races before their love for Garuth caused a rift that would persist until the marriage of Alrik of Valt and Kamala of Krios in 2368. (TNG: "The Perfect Mate")

This planet was only mentioned in dialogue.
Valt, the primary of the Valt system, was located in the Beta Quadrant on a star chart seen in the Star Trek: Discovery episode "Magic to Make the Sanest Man Go Mad".