One system. Trains, metro, ferries, buses and light rail all take an Opal card or a contactless bank card or phone. Tap on and off every time — not tapping off charges the maximum fare.
Fare caps are the important thing: a daily cap, a lower Sunday cap, a weekly cap, and a discount after eight journeys. Once capped, travel is free.
Ferries are the best of it and the best sightseeing in the city. F1 to Manly past the Opera House and out to the heads; F4 to Watsons Bay; F5 to Cockatoo Island; F9 up the river to Parramatta.
Trains are double-decker and radiate from Central. T4 for Bondi Junction; T8 for the airport.
The Metro is driverless, and the city section through the CBD opened in August 2024 — stations at Barangaroo, Martin Place, Gadigal and Central. Older guidance will not mention it.
Light rail runs from Circular Quay along George Street, and from Central to the Fish Market and Dulwich Hill.
Buses are the only way to Bondi Beach — the 333 or 380 from Bondi Junction. No cash on Sydney buses.
The airport exception: the stations at the terminals carry a station access fee on top of the fare, and it sits outside the caps. Bus 400 to Mascot station avoids it.
Helmets are compulsory for cyclists and the law is enforced.
For the detail, see Getting Around Sydney.