I am an Australian citizen, do I need a visa for a 1 week holiday to Hong Kong?

By short holiday I mean a week or so. Also, I will be first travelling to South Korea and possibly Japan beforehand, will I need to apply one or anything if I am arriving to HK from one of these countries and possibly departing HK to another Asian country (possibly Singapore). Do my arrival and departure destinations affect my entry into HK?
Thank you.