However, not all attendees at the "Oscars of the East Coast" party are strictly adhering to the chosen theme.
The annual gala brings in millions for the museum's Costume Institute.
Last year, A-listers from film, music, sports and fashion were asked to dress to the theme of Chinese influences on western fashion - with varying success.
This year, the exhibit is "Manus x Machina: Fashion in an Age of Technology."
The chairwoman of the invitation-only extravaganza is American Vogue editor Anna Wintour, who has been organising the gala for nearly 20 years.
This year, tickets cost $30,000 (Â£20,456) per person - but despite the prices it is one of the hardest parties to get in to.
Privacy of the guests is intensely guarded, and posting on social media after they have walked the red carpet and entered the event has been banned since last year.
Last year, more than $12m was raised for the museum's Costume Institute.
Celebrities at New York's Metropolitan Museum of Art have gone metallic as this year's Met Ball celebrates the convergence of man and machine.