The verdict was reached by a San Diego Superior Court jury of seven men and five women after a trial in Vista, Calif.
Malil, 45, testified in his own defense during the three week trial, claiming he knifed Kendra Beebe in her San Marcos, Calif., home in 2008 when he wrongly thought she was somebody else going after him in the dark.
The two met in 2007 on an online dating service, and they dated for a year in an on and off-again relationship that was, according to Beebe's testimony, volatile. During the trial, she said that Malil was jealous and possessive.
One day before the stabbing, the two also had an argument, witnesses testified, at a beach.
The stabbing incident took place on Aug. 10, 2008, when Malil arrived at Beebe's house and found her in her backyard with another man, musician David Maldonado. According to prosecutors, Malil approached her and stabbed Beebe with a steak knife.
Malil's public defender argued that his client acted in the heat of passion – and that he could be found guilty of attempted voluntary manslaughter but not premeditated attempted murder.
In addition to the attempted murder charge, on Thursday the jury also found Malil, who is also know for a series of 2001 Budweiser commercials, not guilty of one charge of residential burglary.
According to reports, Beebe cried loudly as the verdict was read.
Malil is scheduled to be sentenced on Nov. 18. He faces 21 years to life in prison.