The 28 year-old CEO whose profile status now reads "married" exchanged vows with his medical practitioner fiance at a small ceremony at the groom's home in Palo Alto, Calif.
Guests who were originally invited to a celebration for Chan who just graduated from medical school were surprised to learn that it was a wedding.
Facebook which was formed from Zuckerberg's Harvard dormitory room in 2004 is now worth about $16.9 billion, making it one of the largest companies in the world.