The two men were arrested in Lebanon's Beqqa Vallery, an area near the Syrian border, after they entered the country irregularly, Lebanon's Internal Security Forces said.
The ISF added that the pair were part of a network that smuggled hundreds of people including "Syrians, Lebanese, Egyptians, Palestinians", and others of unspecified African nationalities from Libya to Europe by boat.
They admitted to asking for $3,500 per person and to organising boat trips towards Italy and Greece.
They fled Libya for Syria after a boat they had arranged sank off the coast of the eastern Libyan city of Tobruk, resulting in "dozens of deaths", the ISF added.
One of the men worked with his brothers in Libya and Greece, and they had accomplices in Lebanon's Wadi Khaled, an area in northern Lebanon bordering Syria.
Libya is a major gateway for migrants and asylum seekers attempting treacherous journeys in typically rickety, overcrowded boats in the search for a better life in Europe.
The central Mediterranean route has been dubbed the world's deadliest sea crossing for migrants.
Lebanese authorities have ramped up efforts to confront irregular migration, and say they have prevented thousands of illegal crossings through Lebanon's porous border with Syria in recent weeks.
They often announce they have thwarted smuggling operations by sea or the arrest of both smugglers and would-be migrants.
Lebanon's economy collapsed in late 2019, turning the country into a launch pad for migrants. Lebanese nationals have increasingly been making the voyage towards Europe alongside Syrians fleeing war and economic woes in their country, as well as Palestinian refugees.
Migrants seeking to reach Europe from Lebanon generally head for the east Mediterranean island of Cyprus less than 200km away.