He was 70.
Zewail breathed his last in the US yesterday, Egyptian TV reported.
His mortal remains will be flown to Egypt, where he will be buried, the state-run TV said.
Born on February 26, 1946 in Damanhour city of Egypt, Zewail won the Nobel Prize in Chemistry in 1999 for his pioneering work in femtochemistry.
He received a Bachelor's degree followed by a Master's in Chemistry from Egypt's Alexandria University before taking up the American nationality in 1982.
After moving to the US, Zewail completed his PhD at the University of Pennsylvania and his postdoctoral studies at the University of California, Berkeley.