Kholood al-Sayed, 21, was killed on Monday at her home in the coastal city of Port Said after distancing herself from her intended spouse.
Surveillance footage verified the man's identity and "tracked his movements from the time he left work until he entered the property where the incident occurred, which he then fled," the statement said.
The accused now faces murder charges and the death penalty if found guilty.
The killing is the fourth case of femicide to make headlines in as many months in Egypt where conservative laws and interpretations of Islam have severely limited women's rights.
In a similar case in June, Mohamed Adel stabbed college student Nayera Ashraf to death in nearby Mansoura. A video of the attack was widely shared on social media
The court convicted him and has called for his execution to be broadcast live on television to deter others.
According to Egyptian association Edraak Foundation for Development and Equality, 296 women and girls were killed in 2021.
It said it recorded a total of 813 violent crimes against women and girls last year, up from 415 in 2020.
Nearly eight million women out of Egypt's 100-million population were victims of violence committed by their partners or relatives, or by strangers in public spaces, according to a United Nations survey conducted in 2015.