[1][2] Hinnant's first major role was as Cathy's boyfriend, Ted, on The Patty Duke Show from 1963 to 1965.
Hinnant is best known as a featured performer on the children's show The Electric Company, which aired on the American educational television network PBS from 1971 to 1977.
In 1977, he voiced the Easter Bunny in the Rankin/Bass made-for-television, stop-motion animated feature The Easter Bunny Is Comin' To Town, and in 1980, he provided the voice for the title character Pogo Possum in the direct-to-video feature film I Go Pogo (also done in stop-motion).
His most recent acting roles were an appearance in the PBS science education show 3-2-1 Contact as Flash Jordan in the episode Measurement: How Fast?
Then he retired from television acting and devoted his entire career to voice-over work at the beginning of 1990s, but in 2006 he made appearances in two retrospectives of The Electric Company: one was a PBS pledge drive special, the other was The Best of the Electric Company: Vol.