Vice President Omar Suleiman made the announcement, stating, ""In these grave circumstances that the country is passing through, President Hosni Mubarak has decided to leave his position as president of the republic. He has mandated the Armed Forces Supreme Council to run the state. God is our protector and succor.""
Fireworks, cars honking, flags waving, cameras flashing and more could be witnessed throughout Cairo and elsewhere. Watch some of the celebrations below.
You can also watch live video of the celebrations via Al Jazeera here.