Others on Facebook are filling newsfeeds across the site with congratulations to those who made the cut -- and apologies to their virtual victims who didn't.
"Friendship is a sacred thing and I believe Facebook is cheapening it," he said. "I go on this Facebook, I see people with thousands of what they call friends. This is impossible, you can't have a thousand friends. Here's how you can tell who on Facebook is really your friend: Let's say on Friday, you post a status update that says 'I'm moving this weekend and I need help.' The people that respond, those are your friends. Everyone else isn't."
In response to Kimmel's "holiday," Facebook issued a tongue-in-cheek statement of its own: "Jimmy Kimmel's Facebook campaign is clever so we're keeping him on our friend list for now. But just remember Jimmy, it's one thing to be the "unfriender", but it's a whole different story if you're the "unfriended."
Over the past couple of weeks, Kimmel has continued his campaign, encouraging viewers to drop their fake Facebook friends on "National Unfriend Day."
"It's a special day on which Facebook users, which most of you probably are, without guilt or fear of retribution, can unfriend those people who are not really your friends," he said. "And don't we all have at least one person in our virtual lives we'd like to get rid of? Of course we do, we probably have 100 of them."
He convinced the band WAR to rerecord the lyrics to their hit "Why can't we be friends?" with the refrain "What can't we unfriend?"
And he even asked one of television's most famous "friends," actress Lisa Kudrow, to record a mock PSA for his national holiday.
"Your friends on Facebook are not your real friends. Real friends are people you meet at Central Park. People who watch you play guitar and sing and pretend to like your cat no matter how bad it smells. Real friends have hair styles named after them," she said. "On November 17, dump your fake friends before they ruin your day, your week, your month or even your year. I know friends. I used to be one."