NEW YORK - Mayor Bill de Blasio has been officially sworn into office as the 109th mayor of New York City.

De Blasio first took the oath of office in a small ceremony at his Park Slope home, just moments after ringing in the new year. He was joined by his wife Chirlane, and kids Chiara and Dante.

The inauguration was celebrated on a far grander scale on the steps of City Hall where he took the oath for a second time, as administered by former President Bill Clinton. Former mayors Michael Bloomberg and David Dinkins, and Gov. Andrew Cuomo were among those in attendance.

Everyday New Yorkers from all five boroughs were included in the mix, getting an up-close seat on stage for the swearing in. They included a fast food worker from Brooklyn who's raising three children.

Public Advocate Letitia James and Comptroller Scott Stringer were also officially sworn into office.