TV Tonight reports that Jacobz will replace original presenter Matthew Newton, who pulled out of the show after deciding to return to rehab.
Jacobz has now revealed that he landed the job after getting a telephone call from executives at Channel Seven late last night.
He said: "I wish [Newton] all the best and hope I am going to do as good a job as he was going to do."
Newton was filming the Judges' Houses stage in Dublin when he decided to leave the show. It is unclear whether footage of him at the auditions and Boot Camp will appear in the programme.
Jacobz previously hosted the talent show Popstars in 2004 and has had roles in Home and Away and McLeod's Daughters.
The X Factor premieres next Monday on Seven.