65 MPs supported the bill while 21 from the Harmony party notably abstained.
The adopted declaration stresses that with the abduction and continued illegal detention of Savchenko Russia has violated international rights.
It also expresses concerns about Savchenko's health and asks Russia to free Savchenko immediately as per the Minsk agreement and for humanitarian reasons.
The declaration also asks for freeing other Ukrainian citizens illegally detained in Russia and for the country, a United Nations member, to uphold the organization's human rights statutes.
Rihards Kols (National Alliance), deputy head of the Foreign Affairs Committee, told Latvian Radio before the vote that "the declaration doesn't matter to Russia", however saying that as a democratic country Latvia cannot keep silent over such violations of human rights and international law as these.
MP Lolita Čigāne (Unity) told Latvian Radio 4 that the declaration aims to achieve setting Savchenko free, saying that in 2014, for example, Russia tried embellishing its image by freeing Pussy Riot members and Mikhail Khodorkovsky.
While Sergejs Potapkins of the opposition Harmony party called against supporting the declaration, saying that Latvian lawmakers should not try becoming a substitute for the judicial powers for other countries. He called for working out a declaration that all MPs could support.
AFP news agency reported that a Russian court on March 22 sentenced Ukrainian military pilot Nadiya Savchenko to 22 years behind bars after she was found guilty of involvement in the killing of two journalists in eastern Ukraine.
The court found Savchenko "guilty on all counts" and sentenced her to 22 years in prison and a 30,000-ruble ($440) fine at the end of a trial that has been slammed by the West and Kiev as a political farce.
Savchenko's lawyers have said she would not appeal the verdict given her distrust of the Russian legal system.
The EU and Washington have repeatedly urged Moscow to release Savchenko, while Kiev meanwhile has been pushing for a prisoner swap with Russia.
Savchenko was convicted on charges of abetting the deaths of Russian journalists Igor Kornelyuk and Anton Voloshin, who were killed in shelling in June 2014, two months after the start of the pro-Russian separatist uprising in eastern Ukraine.
She was also found guilty of illegally crossing the Ukrainian border into Russia.
Savchenko, who was serving in a volunteer pro-Kiev battalion at the time, has maintained that she was abducted by pro-Russian rebels before the journalists were killed and then smuggled into Russia.