It is another sign of improving ties between the two countries following the return of Saudi Arabia's ambassador to Beirut after he was withdrawn during a diplomatic rift last year.
Saudi Arabia and fellow wealthy Gulf states were once major donors for Lebanon, but relations have been strained for years by the growing influence of the Iran-backed Hezbollah movement.
Saudi Arabia and Kuwait said on Thursday they will return their ambassadors to Lebanon in response to Lebanese government's pledges to boost co-operation and strengthen ties with the Gulf.
In October, Lebanon’s former information minister George Kordahi made offensive public comments against Saudi Arabia.
In response, Saudi Arabia, Kuwait and Bahrain recalled their ambassadors to the country and asked their citizens to leave Lebanon.