Vostok 2 (Russian: Восток-2, Orient2 or East 2) was a Soviet space mission which carried cosmanaut Gherman Titov into orbit for a full day on August 6, 1961 to study the effects of a more prolonged period of weightlessness on the human body. Titov orbited the Earth over 17 times, exceeding the single orbit of Yuri Gagarin on Vostok 1 - as well as the suborbital spaceflights of American astronauts Alan Shepherd and Gus Grissom aboard their respective Mercury Redstone-3 and 4 missions. Indeed, Titov's number of orbits and flight time would not be surpassed by an American astronaut until Gordon Cooper's Mercury Atlas-9 spaceflight.

The flight was an almost complete success, marred only by a heater that had inadvertently been turned off prior to liftoff and that allowed the inside temperature to drop to 50 °F (10 °C),:113 a bout of space sickness, and a troublesome re-entry when the reentry failed to separate cleanly from its service module.

Unlike Yuri Gagarin on Vostok 1, Titov took manual control of the spacecraft for a short while. Another change came when the Soviets admitted that Titov did not land with his spacecraft. Titov would claim in an interview that he ejected from his capsule as a test of an alternative landing system; it is now known that all Vostok programme landings were performed this way.
The re-entry capsule was destroyed during development of the Voskhod spacecraft.:117

As of 2012, Titov remains the youngest person to reach space. He was a month short of 26 years old at launch.