It is part of the brand’s global "Live feed" campaign where more than 40,000 Subway restaurants across 60 countries will donate meals to local hunger-relief charities.
The "Subway live feed headquarters" activity will pop-up at Madison Square Garden in New York tomorrow. There will be DJ sets, free sandwich samples, giveaways and a performance by Andy Grammer.
Suzanne Greco, president and chief executive of Subway, said: "As a global food company, we are passionate about the fight against hunger. We want to ensure everyone has access to nutritious food.
"On World Sandwich Day, we are offering more than a free sandwich to our loyal customers, we are also offering a chance to fight hunger around the world."