The footage, which has been confirmed as an Internet hoax, mashes up unrelated scenes from a March 17 episode of the FOX animated series to make it as if the show depicted the bombings.
Responding to the act, MacFarlane took to Twitter to condemn it, reported Aceshowbiz.
"The edited Family Guy clip currently circulating is abhorrent. The event was a crime and a tragedy, and my thoughts are with the victims."
The fake clip features Peter Griffin being asked by Bob Costas how he won the Boston Marathon. The following scene shows Peter accidentally blowing up a bridge by dialing a terrorist's cell phone.