An official statement said President Emile Lahoud accepted the resignation of Hariri's 30-man cabinet, from which four ministers had resigned last month to protest the extension of the president's mandate by three years at Syria's behest.
"Confronting the challenges facing Lebanon necessitates a well-banded and united government that will be able to fully assume public affairs," Hariri said in a statement.
"Since these objectives could not be fulfilled due to political obstacles, I found that it is proper that I submit the resignation of my government and apologize for not forming the next one, wishing my successor all success," Hariri added.
Hariri, a self-made billionaire, has been clashing with Lahoud over political and economic reforms. Their political bickering and rifts resulted in paralyzing government performance for more than a year.
Hariri also staunchly opposed the extension of Lahoud's six-year mandate, which was supposed to expire in November.