Russian media claimed it was the harshest sentence given to any woman in the country's modern history.
26-year-old Darya Trepova was convicted of charges of terrorism, handling explosives and using forged documents in relation to Vladlen Tatarsky's death.
Tatarsky had been giving a talk in a cafe in St Petersburg in April 2023 when he was handed a statuette in his likeness.
It contained a bomb, which killed him instantly.
Trepova said she had been set up and says she thought the statuette contained a listening device, not a bomb.
She told the trial she was acting under orders from a man in Ukraine, whom she knew as "Gestalt".
She claims he had been sending her money and instructions for several months prior to the attack.
Trepova said she had gone along with the man's instructions, believing his purpose was to eavesdrop on what he knew about the war, which she opposed.
She showed no visible emotion in response to the sentence and told the court she never intended to hurt anyone and felt "great pain".
Her defense team say they will appeal her sentence. Here's Trepova's lawyer, Daniil Berman.
"It was probably the most severe sentence towards a woman in the history of modern Russia's law enforcement. In my opinion, there was no real grounds for it, even if we assume that Daria is actually guilty as charged."
Russia accused Ukraine immediately after the attack of organizing the blogger's murder.
Senior Ukrainian officials have neither claimed responsibility nor denied involvement in Tatarsky's death, who's real name was Maxim Fomin.
