10 Downing Street is the residence and office of the Prime Minister of the United Kingdom and the headquarters of Her Majesty's Government. It is situated on Downing Street in the City of Westminster in London, England. Number 10, as it is often known, is perhaps the most famous address in London and one of the most widely recognised houses in the world.

Situated in Westminster it is the centre of the United Kingdom government, physically and politically. Not only is Number 10 the Prime Minister's (the "PM") home, it is also a place of work. It has offices for the PM, the secretaries, assistants and advisors, and numerous conference rooms and dining rooms where the PM meets with and entertains other leaders and foreign dignitaries.