The Nigeria international spent last season on loan at West Ham, but he was unable to save the club from relegation from the Premier League.
The 24-year-old forward scored eight goals in 30 appearances for the Hammers during his season-long loan in England.
Serie A giants Inter opted against extending Obinna's contract this summer meaning he was a free agent.
Lokomotiv have now confirmed they have agreed terms with the player, who will formally move clubs on July 1.
"We have agreed a contract with Victor as a free agent," the Russian outfit confirmed. "The agreement with Obinna is for four years."