The 31-year-old had been held in a Florida prison since her conviction for conspiring to influence US conservative activists and infiltrate a powerful gun rights group.
Butina was released on Friday morning and taken into custody by US Immigration and Customs Enforcement authorities before leaving on a direct flight to Moscow, ICE said in a statement.
Maria Butina pleaded guilty in December to one count of conspiring to act as a foreign agent
The Aeroflot plane from Miami landed at Sheremetyevo airport in Moscow shortly before 11:30am (local time).
Butina was scheduled for release in early November but the date was moved after she was credited for good behaviour.
Her sentence included nine months she spent in detention after her arrest in July 2018.
Moscow has denied that Butina was a spy, and Russian President Vladimir Putin previously expressed his “outrage” over her imprisonment.
Maria Butina spoke to reporters after arriving at Moscow airport
The country’s Ministry of Foreign Affairs accused the US of forcing Butina to make a false confession, branding the charges “absolutely ridiculous”.
“It’s not clear what she was convicted of or what crime she committed,” President Putin said in April.
“I think it’s a prime example of ‘saving face’. They arrested her and put the girl in jail.
“But there was nothing on her, so in order not to look totally stupid they gave her, fixed her up, with an 18-month sentence to show that she was guilty of something.”
Maria Butina was convicted of conspiring to influence US conservatives. Pic: Facebook
Butina, a graduate of the American University in Washington, pleaded guilty to conspiring with a Russian official and two Americans to infiltrate the National Rifle Association (NRA).
The group is closely aligned with US conservatives and Republican politicians, including President Donald Trump.
She also admitted creating unofficial lines of communication to try to shape Washington’s policy toward Moscow.
Maria Butina with Alexander Torshin
Prosecutors said Butina arranged dinners in Washington and New York and attended events to meet prominent politicians in an effort to make inroads in conservative political circles.
This was against US law because she did not report her actions to the Justice Department, which requires the registration of lobbyists and those who work for foreign governments in the US.
Alexander Torshin, a deputy governor of Russia’s central bank, was later identified as the Russian official who conspired with Butina.
He did not face any charges but was hit with sanctions by the US Treasury Department.
