The victim was found on Charteris Road close to the junction with Lennox Road at around 6.50pm.
Friends at the scene on Friday said he was Algerian and worked for Deliveroo and UberEats as a delivery driver.
Speaking at the scene on Saturday, Mr Corbyn, whose Islington North constituency includes Finsbury Park, said: “I am totally shocked. This is a very close-knit community, and this is yet another stabbing on the streets of London.
“People should not be carrying knives. A human life has been taken.
“There are a lot of people working as delivery drivers, they must have better conditions of employment and employers must take more responsibility for their safety too.
“Police cuts have meant fewer officers on the streets, and this raises issues of safety in the community in general.”
He added: “Delivery drivers do a great job in London all of the time. Yet they are vulnerable.
“They’re often on zero hours contracts, yet the food they are carrying is insured.
“So the delivery driver is less valuable than the food they are carrying.
“We need to end the whole culture of gig employment.”
Deliveroo and Uber driver Zakaria Gherabi, 37, who knew the victim as “Taki”, also attended the scene on Saturday.
He said he has been the victim of attacks while working as a delivery driver, including in October last year when his attacker punched him in the eye and dislocated his socket.
Mr Gherabi told the PA news agency: “My attackers are still on the streets. The police do nothing.
“It happens. Nobody is going to save you. The company does not care, we are self-employed, but the food we are carrying is insured.
“I knew the victim. He did not do anything, he was a good guy. He was stabbed to death on these busy streets.
“The job is not safe. I don’t feel safe doing it."
Jeremy Corbyn speaks to delivery driver Zakaria Gherabi after the stabbing
On Friday, fellow delivery riders gathered in Stroud Green Road said he had been the victim of a road rage attack following an altercation with a car driver.
Some of those gathered said they had been repeatedly attacked in the neighbourhood by young gang members – often still in their teens.
Many of the riders criticised the companies they worked for and the police for doing nothing to protect them.
The driver who attacked the victim was driving a Volkswagen Caddy, a witness said, and did not try to steal his moped from him.
No arrests have been made and inquiries continue, the Met said.