Moses, 29, has barely featured at Stamford Bridge over the past few seasons, spending most of his time elsewhere on temporary moves.
That will be his fate once more this term, as he penned a loan deal with the Russian club which will run until the end of the season and includes a purchase option.
“Spartak Moscow and Chelsea have agreed the transfer of Nigerian star Victor Moses to our club. The loan agreement with the 29-year-old midfielder is until the end of the season with the option to buy! Welcome, Victor!”
Moses made the move to Stamford Bridge from Wigan in 2012, having begun his career at local side Crystal Palace as a youth.