I am travelling to Australia via Hong Kong. I have a layover time of 16 hours in one of the trips. Please tell me if I need a visa if I stay in the airport and travel from one terminal to the other terminal.
As stated in Timatic, the database used by airlines:
TWOV (Transit Without Visa): - Those who are in direct (Air to Air or Air to Sea) transit if holding confirmed onward bookings, continuing their journey within 48 hours and not leaving the transit lounge.
So if your trip is in a single booking, you do not Need a visa.