The 23-year-old victim was taken to a south London hospital in a critical condition on 11 June.
Police were called to Lucey Way in Bermondsey, where they found the man suffering from stab injuries.
He was pronounced dead on Monday morning. It is the 67th murder investigation in the capital this year.
The Metropolitan Police said the man’s next of kin have been informed and a post-mortem examination will take place in due course.
Appealing for information, the force said the man may have been fatally injured after a fight.
Detective inspector Ian Titterrell said: “At this early stage, we believe an altercation involving a group of males began outside Helen Taylor House in Linsey Street.
“The victim then took shelter at an address on Lucey Way after being attacked.
“We know there were a large number of people in the vicinity at the time of the attack and I am appealing for anyone with information to get in touch.
“Any information will be treated with the strictest of confidence.”