"The board of directors has agreed to terminate his contract. We will now have to look for a new coach," Lokomotiv president Olga Smorodskaya told Russian media.
Semin became the first coaching casualty since the end of the season, his dismissal coming just two days after the big-spending railway side finished the Russian league in fifth place.
They also failed to qualify for the Europa League following a shock defeat by Swiss second division side Lausanne in August.
Semin began his third spell at the helm of Lokomotiv in May 2009, having coached them from 1986-1990 and 1991-2005 when he won two league titles and four Russian Cups.
Local media have linked the 63-year-old with Dynamo Kiev, whom he led to the Ukrainian league title in 2009 before quitting to join Lokomotiv.
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