TMZ reports that the 'I Don't Wanna Be' singer was walking around late on Sunday night when he was approached and assaulted by multiple attackers.
He is said to have been "outnumbered" by his assailants and the motive of the incident is unknown.
DeGraw's representative has revealed that the musician is currently under observation at the city's Bellevue Hospital. Specific details about his injuries have not yet been released.
'I Don't Wanna Be' serves as the theme song to The CW drama One Tree Hill.
DeGraw released his debut album Chariot in 2003 and will release a third LP, entitled Sweeter, on September 6.
He was on tour with with Train and Maroon 5 and intended to perform in Saratoga Springs on Tuesday night.
Watch Gavin DeGraw's video for 'I Don't Wanna Be' below: