Schmidt wrote that he will remain at Google as executive chairman. Google co-founder Larry Page will replace Schmidt as the new CEO on April 4.
News of the shakeup came as a shock to some Twitter users, while others seemed less surprised.
We've gathered a sampling of the reaction from tweeters. Vote for the best reaction, and tell us if you were shocked to hear of Schmidt's departure. To learn more about this developing story, check out our coverage of Google's CEO shakeup.