And the holiday ranks second, just behind Christmas, when it comes to spending on d?cor.
Kendal Perez is the blogger behind "HassleFreeSavings.com."
And before you spend money on d?cor items, she suggests checking websites like Pinterest for inexpensive Do-It-Yourself ideas.
She says, "I was just on there the other day and they had lots of great ideas including a pumpkin with a hole in its mouth that had a stuffed jean pant in there, so it looked like it was eating the person. There's lots of really fun, creative ideas that you can do for free or for very cheap."
And shop for costume items at thrift stores like Goodwill. She explains, "Haunting your local thrift shop is a great way to save money on Halloween costumes. Not only do they have cheap pre-made Halloween costumes, but they also have really cheap clothing that you can use to put together your own costumes.
Perez also says Halloween is a great time to use coupons -- for everything from candy to cloth.
"There are some good deals and coupons to be had,"Perez says. "And for people who don't like to clip coupons, there's the free Coupon Sherpa mobile app. It's really easy, it has all the coupons in one app, on your smartphone."
You can also look for freebie deals, like a Trick-or-Treat bag from York Photo or scented candle from Bath and Body Works.
And you can download free printables for items like decorations and invitations.
Finally, resisting the temptation to buy candy for as long as you can will pay off -- not only for your diet, but for your wallet.
Perez explains, "Waiting until the last minute to buy Halloween candy is a good idea becuase retailers are kind of eager to get that stuff off their shelves as we get closer to the holiday itself. Because, of course, the day after Halloween, you're going to see holiday candy up there."
To get more of Perez's Hassle-Free Savings tips, click here.