He has undergone specialised military training abroad, including in the United States, Germany and Italy.
Differences between the US-backed parliamentary majority and an alliance of opposition groups led by Hezbollah, a Shia organisation, had delayed the appointment of a new army commander.
General Shawki al-Masri, the army's chief of staff, has been acting as head of the army since Sleiman was elected president on May 25.
Observers say the 60,000-strong army has become more of a peacekeeping unit than an offensive force.
Strengthening the army has been part of US policy towards Lebanon.
Since 2006, Washington says it has committed more than $410 million in security assistance to the army, including training, vehicles and ammunition.