The Prime Minister visited Tate Modern on Tuesday morning to deliver a speech to arts leaders celebrating the "renaissance of British culture".
"London has become the creative capital of the world," Mr Blair told the invited audience.
The speech followed a seminar hosted by Mr Blair at Downing Street last week. Guests included Tate director Sir Nicholas Serota and National Theatre artistic director Nicholas Hytner.
Mr Blair singled out the National Theatre for particular praise: "The success of Alan Bennett's The History Boys is a good example. Its journey on an international tour and into the West End was all based on its time at the National Theatre, but not funded by it. It has brought earnings of £1 million back to the National Theatre to be invested back in the programme."
The Prime Minister also looked forward to the cultural programme surrounding the 2012 Olympic Games, in which the SE1 area is expected to play a prominent role:
"First, we need to remember that the Cultural Olympiad offers a fabulous opportunity. We have on the horizon a four-year festival at which we can exhibit a modern, outward-facing Britain. The Olympic victory was a vindication of the cultural face we now present to the world."
Mr Blair added: "When you are searching to show how things have changed you are usually seeking a policy that somehow embodies it. Perhaps it is free entry to museums. But actually the crucial thing is not the policy but the fact that, as Nick Serota said to me recently, museums now just "feel" different. They have a different atmosphere."