A 23-year-old man will appear in Wollongong Local Court on Friday charged with aggravated sexual assault and assault occasioning bodily harm.
Police said the 19-year-old female victim made a complaint against the man at Wollongong Police Station on Thursday afternoon.
The alleged accused and victim were previously in a relationship, police said.
Following investigations, police attended a private residence and arrested the man.
The man was refused bail and will appear in Wollongong Local Court on Friday.