The appointment of retired general Michel Aoun, 81, came after he gained the backing of the former Lebanese prime minister Saad al-Hariri, Riyadh’s preferred leader, and further edges the balance of power in the region towards Iran and its allies.
The Maronite Christian former general secured 83 votes in the 128-seat chamber when MPs convened at noon (1000 GMT) Monday for their 46th attempt to choose a head of state.
Aoun was elected after four rounds of voting during the session.
His candidacy was blocked by the rival, Sunni-dominated Future Movement until a deal was struck earlier this month.
It will reportedly see the Future Movement’s leader, Saad Hariri, become prime minister.
Addressing the parliament after the voting, Aoun described political stability as his top priority and said his government would deal with terrorism “preemptively and preventively” until it is uprooted.
Saudi Arabia had been vehemently opposed to Aoun’s nomination, fearing he will consolidate Iran’s influence on the brittle state, which has remained a vulnerable state since the end of its destructive civil war 25 years ago.
Lebanon has been without a head of state since Michel Suleiman stepped down at the end of his term in May 2014.