Las Vegas Currency Guide
Las Vegas uses the US Dollar.
With much to spend your money on, Las Vegas is practically a city of ATMs with locations all throughout the casinos, resorts and then some. If you plan on withdrawing money or using your credit card while travelling, don't forget to notify your bank before you go for security purposes and to check what international withdrawal fees may apply to your card.
Before you leave home, it is important to convert some of your Australian Dollars into US Dollars to have ready to go when you arrive in Las Vegas for tips, snacks, cab fare, whatever. US Dollars are available to pre-purchase from Travel Money Oz before you fly.
If you plan on holding onto your money in Las Vegas, consider bringing a credit card or travel money card with you instead of carrying a lot of cash. If you don't have a credit card, consider a pre-paid Cash Passport, which lets you access your money in the form of US Dollars from ATMs and also use wherever MasterCard is accepted.