The incident unfolded just before 3 p.m. in the area of Green Tree and Coral Tree lanes as police were called to the area on a report of a man attacking a woman.
When officers arrived, they saw a man actively attacking a woman with a knife outside a home, according to a police spokesman.
The department says when the officers tried to stop him, he started advancing toward them with the knife.
Officers shot the man.
Both the suspect and victim were declared dead at the scene. A knife was recovered at the scene.
Irvine police later identified the suspect as Paul Parvea Montazer, 37, of Las Vegas.
The victim was his mother, 72-year-old Parvin Montazer of Irvine.
"This is a tragic situation, and our hearts go out to all involved," said Kyle Oldoerp, spokesman for Irvine police.
It was the second deadly officer-involved shooting this week in Irvine, a rare occurrence in a city often ranked among the safest in the country for its size.