The British actor got involved in an altercation with security guards at CBS Studios, TMZ reported.
According to sources, Dillane tried get through a security checkpoint when he visited the TV studio at the time.
When security guards tried to stop him, he allegedly struck one of them and was later detained with a citizen's arrest. He's eventually booked for battery once the LAPD arrived at the scene.
It's still unclear why Dillane was at the CBS lot, since his show doesn't shoot there.
Dillane, the son of "Game of Thrones" alum Stephen Dillane, plays recovering drug addict Nick Clark on "Fear the Walking Dead" that airs on AMC.
His credits include "Harry Potter and the Half-Blood Prince", in which he played the young Tom Riddle, and "In the Heart of the Sea".