Originally Posted by Himeno

There are 2 bus companies on the Canberra-Sydney route. Greyhound and Murrays.
Murrays has buses departing Canberra at midnight and hourly between 4am and 6pm (7pm some days). They stop at SYD T1 (outside the QF I>D connections area) on the way to/from Sydney Central.
Greyhound has 6 services a day. 5 stop at T1, 3 stop at T3 (as required by bookings).