Kosmos 419 (Russian: Космос 419 meaning Cosmos 419), also known as 3MS No.170 was a failed Soviet spacecraft intended to visit Mars.

The spacecraft was launched on 10 May 1971, however, due to an upper stage malfunction, it failed to depart low Earth orbit.

In 1971, Mars was at its closest to Earth since 1956, and in May of that year, both the Soviet Union and the United States made new attempts to reach the Red Planet.

Due to its low orbit, which quickly decayed, Kosmos 419 reentered the Earth's atmosphere on 12 May 1971, two days after launch.

[4] The designation Kosmos 419 was a generic name given to Soviet spacecraft operating in Earth orbit; at the time, Soviet planetary spacecraft which failed to depart Earth orbit would be given designations in the Kosmos series to disguise the failure.