D'Agosto will debut in the Batman prequel series as the alter-ego of district attorney-turned-crime boss Two-Face.
The 34-year-old actor has hinted that Gotham producers expect Dent to take a central role in future seasons of the Fox programme, reported Deadline.
"I become a regular in season two. So you'll see a lot more of me in season two, which we all hope happens."
D'Agosto added that Batman fans should expect hints about Dent's future as a criminal in upcoming episodes.
It was announced earlier this month that 'Gotham' will also explore the origins of DC Comics villain Scarecrow.