Patrick Frazee was convicted of first-degree murder and other charges after the jury deliberated four hours.
Less than an hour later, a judge sentenced him to the life term, plus 156 years, the mandatory sentence after prosecutors previously decided not to seek the death penalty.
Prosecutors said Frazee, 33, killed Kelsey Berreth, a 29-year-old flight instructor and the mother of their 1-year-old, in her home.