The jury verdict against Maria Kukucova, 26, came at the end of a week-long trial in the southern Spanish city of Malaga. During the trial, the model testified that she had never meant to harm Andrew Bush, saying that she had acted in self-defense.
Prosecutors sought 20 years in prison for Kukucova, but the court has not yet handed down a sentence. It was not immediately clear when sentencing might take place.
The murder occurred when Bush returned home unexpectedly from a trip to Britain. The two had broken up about a month before the killing, following a relationship of more than two years.
Kukucova testified she spent two days alone inside his house and that he arrived after a trip with a Russian girlfriend, Maria Korotaeva. When he saw Kukucova was there, Bush told Korotaeva to go outside.
After the killing, Kukucova ordered Korotaeva to get out of Bush's Hummer vehicle and drove away. She fled to Slovakia but turned herself in to police four days after the killing. She was extradited to Spain a month later.