Lebanon s President Michel Aoun (L) meeting with Prime Minister Najib Mikati (R) at the presidential palace in Baabda, east of the capital Beirut, on April 7, 2022. AFP
The foreign ministry "announces the return of the ambassador... to the sisterly Republic of Lebanon", read a statement carried by Saudi state media.
A diplomatic crisis erupted last October after the then-information minister was quoted criticising the Saudi role in Yemen, where a grinding war has produced what the UN describes as the world's worst humanitarian crisis.
George Kordahi, who has since resigned, said in a television interview that the Houthi rebels fighting Yemen's internationally-recognised government were "defending themselves... against an external aggression".
He said "homes, villages, funerals and weddings were being bombed" by the Saudi-led coalition, and called the war in Yemen "futile".
The Houthis are backed by Saudi arch-rival Iran, which has significant influence in Lebanon, where it backs the powerful Shia movement Hezbollah.
In response to the remarks, Riyadh recalled its ambassador and ordered Lebanon's envoy to leave the kingdom. Its Gulf allies the United Arab Emirates, Bahrain and Kuwait followed suit, expelling Lebanese envoys.
Following announcement of the Saudi decision, Kuwait also announced Thursday the return of its ambassador to Beirut.
The row, which has also seen Saudi Arabia ban the imports of Lebanese goods, was a blow to a country already in the grip of crippling political and economic crises.
Lebanon, which had been counting on financial assistance from the Gulf to rescue its economy, welcomed the Saudi announcement.
"We highly value the kingdom of Saudi Arabia's decision to return its ambassador to Lebanon and we stress the fact that Lebanon is proud of its Arab allegiance and is adamant on maintaining the best ties with Gulf nations," Prime Minister Najib Mikati tweeted.
'Worries' over Hezbollah
Lebanon's Interior Minister Bassam Mawlawi also praised the move.
"Once again the Kingdom of Saudi Arabia has proven, by the return of its ambassador... that Lebanon is in its heart and conscience and that it will never abandon it," Mawlawi said.
"We will continue to work on strengthening ties and we will not allow any harm or offence to come its way from now on," he added.
Saudi Arabia had stepped back from its former ally Lebanon in recent years, angered by the influence of the Hezbollah.
Riyadh has long accused Tehran of supplying the Houthis with sophisticated weapons and its Hezbollah proxy of training the insurgents -- charges Iran denies.
Saudi Arabia said in December it had "evidence of involvement of Lebanon's terrorist Hezbollah in Yemen" including using the airport in Yemen's capital Sanaa "to target the kingdom".
Saudi Foreign Minister Prince Faisal bin Farhan had blamed deteriorating ties on Hezbollah and Iran's dominance over Lebanese politics.
"There is no crisis with Lebanon but a crisis in Lebanon because of Iranian dominance," he told Al-Arabiya television in October.
"Hezbollah's dominance of the political system in Lebanon worries us," he had said.
The return of the ambassador, Saudi state media said Thursday, came "in response to the calls and appeals of the moderate national political forces in Lebanon".