On Friday morning Mayor of London Boris Johnson cut a ribbon to mark the official opening of the observation decks at the top of the Shard.
The first paying visitors to the attraction were greeted by the Shard's developer Irvine Sellar and architect Renzo Piano.
The first 200 visitors to the attraction were also given a commemorative photographic print of The Shard.
The attraction claims to have sold more than 130,000 advance tickets and expects to lure one million visitors to London Bridge in its first twelve months. The first day was declared a sell-out in mid-December.
96 people are employed at The View from The Shard and almost half ofthe staff are from Southwark, with a further quarter from the neighbouring boroughs of Lewisham and Lambeth.
"This stunning new visitor attraction is a fantastic addition to London's tourist offer," said Boris Johnson.
"From these dizzy heights the greatest city on earth, from historic to modern, is spread out below in all its magnificent glory and visitors will be mesmerised by this experience.
"I am confident that The Shard and the huge London Bridge Quarter development will change the face of this important part of our city attracting new businesses and creating thousands of jobs in the coming years."
Irvine Sellar said: "There is no doubt that The View from The Shard will be one of the leading attractions in London, complemented by the restaurants – Aqua and Oblix – bars and the Shangri-La Hotel at The Shard, which will all open later this year.
"It is an integral part of our vision that The Shard and London Bridge Quarter will form a unique and inclusive area at the heart of a community that has a long history and huge potential for growth."
Guests at the official opening party on Thursday night included former London Mayor Ken Livingstone, Southwark Council leader Peter John, Simon Callow, Pixie Lott, Terry Wogan, Dan Snow, Rachel Whiteread and Peter Ackroyd.
Tickets to visit the attraction cost £24.95 in advance, £29.95 for a same-day booking or £100 for immediate entry.
• See our gallery of pictures of SE1's newest – and highest – visitor attraction.