The fourth season of On Cinema at the Cinema began airing January 8, 2014.

After resolving his blood clots, Tim faces a new medical challenge this season, namely diabetes. He chooses to circumvent traditional medicine, however, by treating his condition holistically. To that end, he enlists an acupuncturist, Dr. San, who treats Tim with needle therapy. However, thanks to Dr. San's unsanitary needles, Tim develops a crop of infected sores at the insertion sites. He finally fires Dr. San, who disappears. Tim subsequently chooses to treat his diabetes via traditional means, and recovers fully by the end of the season.

Gregg continues his 500 Movies in 500 Days campaign. At his last update, in episode 6, he had watched 127 films. In that same episode, with Tim out for medical treatment, Gregg made his debut as the host of On Cinema, with Larry Turman as special guest.

Other highlights include the announcement of Decker in episode 8, and the revelation at the end of episode 10 that Ayaka is pregnant with her and Tim's child (eventually born as Tom Cruise Heidecker Jr.).

The Second Oscar Special took place between episodes 8 and 9.