Byblos is 37 km north of Beirut and most visitors arrive from there. The most convenient option is a shared service taxi (service) from the Charles Helou bus station in Beirut — these leave when full and the trip takes 45 minutes to an hour depending on traffic. The fare is very cheap by regional standards. OCFTC buses also run the route from Charles Helou, slower but even cheaper.
Private taxis from Beirut can be arranged through hotels or apps, and a driver hired for the day allows you to combine Byblos with other coastal stops (Batroun is 20 km further north, and the historic towns of the Keserwan are inland). Car rental is available in Beirut for those who prefer flexibility — the coastal highway north of Beirut is straightforward driving once out of the city.
There is no airport near Byblos; all international arrivals use Rafic Hariri International Airport in Beirut.