Police said they were called at 5.15am after the man was spotted scaling the outside of the building in London Bridge.
A Met spokesman said the man was spoken to inside the building by police but had not been arrested.
The building is the tallest building in the UK around 310m tall and the man was filmed near the 95-storey skyscraper’s pinnacle.
One eyewitness tweeted: “At least one person climbing up the outside of The Shard in central London.
“Two police cars, two ambulances and a drone on the scene.”
Another wrote on Twitter: “The guy’s got to the top and is being spoken to by the police.”
A man who claimed to know the daredevil told The Mirror how he got onto The Shard.
He said: “He ran over London Bridge Station, got a boost from someone and did a pull up onto it. He used a few suction cups at the start of it but was then climbing free solo.”
A police spokesman said: “Police were called at 5.15am on Monday following reports of a ‘free-climber’ on The Shard.
“Emergency services attended and the man went inside the building where he was spoken to by officers. He was not arrested.”