The Lebanese foreign ministry confirmed that Nasir al-Jundi was released on Tuesday afternoon and was driving his lorry home.
The wife of one of the three Lebanese drivers, Nada Sayyur, said her husband, Qasim Murqbawi, had telephoned her from Iraq. "He said he had been freed, and that his captors had taken nothing from him," she said.
Lebanese Businessman Antoine Antun was also released on Tuesday. His relatives said on Monday his Syrian driver, Isa al-Shaik Awad, had been freed and had called them from Baghdad.
The three were among four men captured on Thursday on a road between Baghdad and Ramadi, an area west of Baghdad where suspicion of foreigners runs high.
Two Jordanian drivers who were released early on Tuesday had been held for two weeks by the so-called Mujahidiin Corps.
The group had demanded the drivers' company stop working with the US military occupying Iraq.
"My brother phoned me saying he was fine and was freed and would be heading home on Tuesday with his colleague," said Umar al-Udwan, brother of Fayiz Saad al-Udwan, one of the drivers.
Iraqi police freed four other Jordanian hostages in a raid on their captors' hideout last week.