Having authored a comic strip in his hometown newspaper at age eight, the Connecticut-born MacFarlane became interested in pursuing a career in animation a few years later after viewing a Nickelodeon TV special profiling a young animator. He set out to follow that path and headed to the Rhode Island School of Design, majoring in animation with the goal of working for Disney. As MacFarlane began to find his own voice and learned more about the business end, he turned his attention to opportunities other than Disney ("It was Disney or nothing then," he later quipped. "Like a lot of animators, I felt Disney is God. Now, it's become Disney is Satan.") A RISD professor sent MacFarlane's thesis film to Hanna-Barbera, who hired him after his 1995 graduation.

Relocating to L.A., he soon began writing and directing shorts and contributing to such series as "Johnny Bravo" and "Cow & Chicken" (both Cartoon Network). MacFarlane soon caught the attention of the executives at Fox who, impressed with the quality of the piece and the dedication evident in his work, originally offered him a deal to create featurettes to run on the network's late-night Saturday comedy series "Mad TV". The deal fell apart, but Fox did not want to lose MacFarlane or his talents. Instead, the network gave him $50,000 to produce a partial pilot for a comedy series. MacFarlane turned in a polished and complete episode, something that was "almost unheard of at that price,” according to Fox vice president Mike Darnell. The pilot was enough to clinch a series deal and "Family Guy" was launched in the prestigious post-Super Bowl slot in January 1999 but the series struggled thereafter and ended its run in the summer of 2000.

The show continued to run throughout 2001, but was finally axed from the schedule by Fox in February 2002. Though the setback caused some dismay, nothing compared to MacFarlane’s brush with fate: he was booked on one of the planes that was crashed into the World Trade Center on September 11, 2001, but a mix-up caused him to miss his flight. This good fortune carried over to his career when Fox made another unprecedented move: they brought the series back in early 2005. Then-Fox president Gail Berman said, “We think it will be bigger than ever,” citing DVD sales and a successful run on the Cartoon Network. As the fourth best-selling television series ever on DVD, MacFarlane credited fans for helping the show return to network.

Along with the return of “Family Guy,” MacFarlane created a new animated series, “American Dad” (Fox, 2005- ). Spawned from the divisive cultural and political atmosphere surrounding the 2004 election, “American Dad” is about a rabid, trigger-happy CIA agent obsessed with national security trying to raise a family that includes an ultraliberal daughter, an effeminate alien living in the attic and a German-speaking, sexually-obsessed goldfish which was the result of a CIA experiment gone horribly awry. Meanwhile, MacFarlane went into development on a film version of “Family Guy,” setting himself up to make his feature directorial debut.