The US leader recalled the many and diverse roles played by the veteran actor - who was found dead in an apparent suicide in his home in California yesterday (11.08.14) - in a touching statement on behalf of himself, wife Michelle and their daughters Malia, 16, and Sasha, 13.
He said: ''Robin Williams was an airman, a doctor, a genie, a nanny, a president, a professor, a bangarang Peter Pan, and everything in between. But he was one of a kind.
''He arrived in our lives as an alien - but he ended up touching every element of the human spirit.
''He made us laugh. He made us cry. He gave us immeasurable talent freely and generously to those who needed it most - from our troops stationed abroad to the marginalised on our own streets.''
The president went on to offer condolences to the star's family - wife Susan Schneider and children Zak, 31, Zelda, 25, and Cody, 23 - friends and those he had helped.
He added: ''The Obama family offers our condolences to Robin's family, his friends, and everyone who found their voice and their verse thanks to Robin Williams.''
Robin - who shot to fame in TV show 'Mork & Mindy', in which he played an alien who came to live on earth - was found dead in his home in Tiburon, yesterday morning in what is believed to be suicide via asphyxiation.
An investigation into the exact cause of death is currently underway and a forensic examination is scheduled to take place today (12.08.14) with subsequent toxicology testing to be conducted.
A spokesman for the Marin County Sheriff's Department in California
explained: ''An investigation into the cause, manner, and circumstances of the death is currently underway by the Investigations and Coroner Divisions of the Sheriff's Office.
''At this time, the Sheriff's Office Coroner Division suspects the death to be a suicide due to asphyxia, but a comprehensive investigation must be completed before a final determination is made.''