| Kosmos 2105 | |
| Mission Type: | Early warning |
| Cospar Id: | 1990-099A |
| Satcat: | 20941 |
| Mission Duration: | 4 years |
| Spacecraft Type: | US-K |
| Launch Date: | UTC |
| Launch Rocket: | Molniya-M/2BL |
| Launch Site: | Plesetsk Cosmodrome |
| Orbit Reference: | Geocentric |
| Orbit Regime: | Molniya |
| Orbit Inclination: | 63.2 degrees |
| Orbit Period: | 717.60 minutes |
| Apsis: | gee |
Kosmos 2105 (Russian: Космос 2105 meaning Cosmos 2105) is a Russian US-K missile early warning satellite which was launched in 1990 as part of the Russian Space Forces' Oko programme. The satellite is designed to identify missile launches using optical telescopes and infrared sensors.
Kosmos 2105 was launched from Site 16/2 at Plesetsk Cosmodrome in Russia. A Molniya-M carrier rocket with a 2BL upper stage was used to perform the launch, which took place at 02:33 UTC on 20 November 1990. The launch successfully placed the satellite into a molniya orbit. It subsequently received its Kosmos designation, and the international designator 1990-099A. The United States Space Command assigned it the Satellite Catalog Number 20941.
It re-entered the Earth's atmosphere on 21 January 2008.