|Affiliation:|| Romulan Star Empire|
|Location:||Chaltok system, Nimbus sector, Tau Dewa sector block, Beta Quadrant|
|Dominant Species:||Romulan, Reman, Yridian|
Chaltok IV housed a Romulan research outpost in the 2260s. The planet was almost destroyed in a polaric ion energy explosion in 2263, which led to the signing of the Polaric Test Ban Treaty in 2268. (VOY episode: "Time and Again"; STO mission: "The Price of Neutrality")
- The video game Conquest mistakenly lists this world's polaric ion accident as occurring in the year 2371, the date that the Voyager crew remembered the event in "Time and Again".
By 2409 Chaltok IV was home to a predominantly Yridian colony on the site of the old research outpost. The newly formed Romulan Republic suspected that it was being used for weapons smuggling and Commander Nadel dispatched the Virinat Survivor to investigate. They discovered that Lortrix, the Reman head of the colony, was funneling weapons to the Hirogen, and were then attacked by the hunter race. The Survivor defeated their away teams and then returned to their ship, whereupon they activated an autonomous missile satellite in orbit of the planet to help them destroy the Hirogen ships.
After this, the IRW Aethra under the command of Charva decloaked in front of them. Charva claimed that D'Tan's Republic was a terrorist organization and not worthy of the Survivor's allegiance. (STO mission: "The Price of Neutrality")