Hitto’s resignation came nearly four months after his appointment and having failed to form so-called opposition interim government.
"I announce I will not continue in my capacity as prime minister tasked with leading the interim government, though I emphasize I will continue working for the interests of the revolution and towards achieving its objectives," Hitto said in an online statement.
His resignation comes two days after secular dissident Ahmad Assi Jarba was chosen to lead the so-called opposition National Coalition.
Jarba is seen as close to Saudi Arabia, which opposed the selection of Hitto to head the interim government in March.
Dissidents say Hitto, whose candidacy was backed by Qatar, was unable to work because of divisions within the Coalition.
Hitto said he decided to resign in order "to help... the Coalition's new leadership to act according to its political vision, especially with regards to the interim government and its executive functions".
Hitto, a naturalized American citizen, won an election in Istanbul after 35 out of 49 coalition members voted for him following some 14 hours of discussion in a closed meeting.