All 128 lawmakers voted in favour of the resolution, which labels Russia a terrorist state.
Lithuania's parliament has unanimously voted to recognise the Russian invasion of Ukraine as an act of "genocide".
All 128 lawmakers in the Seimas approved the resolution on Tuesday, which also labels Russia a terrorist state.
"The Seimas unanimously adopted a resolution by which the Lithuanian Parliament recognised the war waged by the Russian Federation against Ukraine as genocide of the Ukrainian people," a statement read.
"The Seimas states that the Russian Federation, whose military forces deliberately and systematically target civilian targets for bombing, is a state that supports and commits terrorism."
Lawmakers referred to specific allegations of Russian war crimes in Bucha, Irpin, Mariupol, Borodyanka, and Hostomel.
Russia has denied the allegations of war crimes, labelling the images of dead civilians in Bucha "a dangerous and serious provocation".
The Lithuanian resolution had been proposed by a number of MPs, including the parliament's Deputy Speaker, Paulius Saudargas.
"Since the time of the Tsars, Russia has been a basically autocratic state, and Putin is continuing the work of Stalin," he told lawmakers.
"The genocide began even then, and Putin's Russia is simply the reincarnation of Stalinist Russia - the Soviet Union".
Lithuania has called on NATO, the UN, the EU and other international bodies to also recognise the war in Ukraine as genocide and to hold Russia accountable for war crimes.
MPs have also called for a special International Criminal Court to be set to investigate the invasion of Ukraine.