Anthony DeMartino or Mr. DeMartino to the students is a history teacher at Lawndale High. His most notable characteristic is his bulging eyes, one of them occasionally popping out and veined when angry, usually because of Kevin Thompson. He truly wants to be a good teacher, but he uses the students' apathy as an excuse to lash out and yell at them, which has very little, if any effect. As a young boy, Anthony attended military school because his mother did not want her dates to know that she has a son. It appears that he has been resentful of this course of action ever since. Because of his teaching career, he has a very low income and he has been shown getting free samples from grocery stores as his source of nutrients. Anthony is impressed with Daria Morgendorffer's actual intellect, but more frustrated with Kevin's idiocy yet football success. He usually deals with Kevin and Brittany Taylor's naitivitae by taking advantage of them with sarcasm.
In the special, "Is It Fall Yet?" he bonded with the younger kids after making a bully cry, and later threw a sink out the window (a la "One Flew Over the Cuckoo's Nest"). He said the experience inspired him to teach again.
Voiced by Marc Thompson