The 40-Year-Old Virgin star was found guilty of viciously stabbing Kendra Beebe after a three-week trial in September (10).
Malil claimed he had never intended to hurt Beebe and had acted in self defence when he lashed out in the dark during the incident in 2008, stabbing her more than 20 times.
He told the jury at California's San Diego County Superior Court that he thought he was being attacked from behind following a bust-up with Beebe's pal David Maldonado.
He was also found guilty on a charge of assault with a deadly weapon.
Malil, 45, was sentenced in court on Thursday (16Dec10) when Judge Harry Eilas ordered him to serve life behind bars, with the possibility of parole in nine years' time.