All sites in this post are either Australian or ship to Australia.
Another site you probably already knew about, Missguided has a pretty extensive range of formal dresses, of all different styles and lengths. Plus, join their mailing list and get 20% off. Nice!
This amazing site offers knock-off versions of dresses that celebrities have worn to red-carpet events. They're surprisingly good quality, and each dress has reviews and photos uploaded by real-life people who have bought it, so you know what you're getting. There are also a ton of reviews of dresses on their Facebook page. Tip: Use the search function on the website to search for your favourite celebrities.
5. Ho Dress
6. Belle Wishes
7. Jade Gowns
Jade Gowns has a great mix of dresses that range from short to long and everywhere in between. Each dress comes in so many different colours, it's impossible not to find something you'll love.
12. Your Closet
If you don't want to drop a ton of cash on a dress that you mightn't wear again, you should consider renting. Your Closet has dresses from designers like Alex Perry, Camilla and Marc, and Josh Goot. All you have to do is order it online, wear it, and return it via post a few days later. Easy!