After nearly 10 grueling months behind bars in Russia, Brittney Griner is finally heading back home.
U.S. officials said Thursday they've struck a deal with the foreign country ... agreeing to a prisoner swap to free the WNBA star.
It's a 1-for-1 trade ... with the U.S. slated to send over Russian arms dealer Viktor Bout -- aka the "Merchant of Death" -- in the swap.
Griner has been detained in Russia since February -- after she was accused of bringing hashish oil in her luggage to a Moscow airport.