Among the 171 guests present were Kevin Spacey, Tom Hanks and director Tim Burton and his partner Helena Bonham Carter.
Virgin boss Richard Branson was there, as was Prime Minister David Cameron and his predecessors Tony Blair and Gordon Brown.
A long day of public appointments had done nothing to dent the enthusiasm or energy of the high profile guests, who smiled warmly throughout.
Mr Obama paid tribute to the Queen's "lifetime of extraordinary service to her nation and to the world."
His wife Michelle looked stunning in a Tom Ford gown, accessorized with white gloves and a jewelled clutch.
During their time in the capital the US visitors are staying in the Belgian suite – the same one used by the Duke and Duchess of Cambridge on their wedding night.
