A super power in the Small Magellanic Cloud, formally one of Elgava's expanded territories rich in resources which successfully declared its independence after a war. Kalymnos is responsible for much of the raw material mining Elgava relies upon, and boasts a strong and vocal military. Kalymnos' relationship with its neighbour Nova Nacio has been rocky at best throughout the years, due largely to Nova Nacio's acquisition of several planets Kalymnos had discovered first.
Kalymnian ships have the strongest armour in the SMC, yet sacrifice mobility and speed. Pirate activity in the region is so pervasive that their military has a special branch named the "Sector Security Agency," while the rest of their military patrols the borders between them, and Nova Nacio.
- Commander Silas Ioannov: Veteran soldier who doesn't allow the friction between Kalymnos and Nova Nacio to affect his pursuit of equality and justice. He is also the Sector Security's commanding officer.
- Ensign Belin Pappas: A carefree yet decidedly focused man, whose cavalier and womanizing habits are offset by his loyalty and dedication to his duties.
- Ensign Vlasis Delis: Pappas' partner who values discretion and patience, but is deeply affected by the feud between Kalymnos and Nova Nacio, much like many of his fellow soldiers.
During the course of the game, when the Irvest sector is discovered, both Kaylmnos and Nova Nacio race to colonize the area. However, during a scanning pass, a Nova Nacion ship flies too close to a Kalymnos controlled planet. The ship finds itself surrounded by Kaylmnos forces and is told to flee. Caught in a panic and outrage at their position, the Nova Nacion vessel fires on one of the ships. Unfortunately, the vessel that was hit was a carrier, whose occupants were mainly non-combatant colonists. Outraged at the turn of events, Kalymnos swiftly retaliates by creating what they term the "Bactria" line; a blockade which cuts off two Nova Nacion planets from Nova Nacion territory. These events ignite a war between the two nations, with the player in the center of it, leaving them to decide which side they will support.
- Most of the nations in Infinite Space have naming conventions that seem to have analogues in real life. Kalymnos appears to be based off of Greece.