The ruling is a judicial landmark, and may pave the way for increased scrutiny of Russian soldiers and their conduct in the war-torn province.
Yury Budanov, who was stripped of his military rank and medals, was convicted of kidnapping, murder and abuse of power, Interfax reported. He is the highest ranking officer to have been tried for crimes committed during the Chechen war.
"This sentence is too harsh," Budanov’s lawyer, Alexander Tulimov, told reporters. He has promised to appeal the sentence.
Temporary insanity plea
The tank commander, 40, admitted killing Kungayeva in March 2000 though used as his defence, a plea of temporary insanity, saying he mistook her for a sniper.
He will serve his sentence in a maximum security prison.
Elza Kungayeva was abducted by Russian troops from her home village of Tangi-Chu in Chechnya, taken to a military base, raped and strangled.
One of Budanov's subordinates was charged with the sexual assault.
Budanov’s trial was prosecuted in a military court in Rostov-on-Don, southern Russia. It was regarded, by both the International community and human rights groups, as a test of Russia's resolve to prosecute atrocities committed by its troops.
Human rights abuses condemned
Still, only last month Russia was condemned by the Council of Europe for its human rights abuses in the break-away region. The committee combating torture accused Russia of persistent violations of basic human rights.
War between the Russian army and the fighters has raged in Chechnya for a decade and has cost tens of thousands of lives.
Elections, scheduled for October, will give the southern Russian province its first elected leader since 1997. They are also are a key part of the Kremlin's peace plan for the region.