If I pay for business supplies using a gift card can I still list them in my expenses section?

Yes, you can deduct any expenses  that are ordinary and necessary for the business. The source of the money is not relevant.

The gifted money was your money, the same as the cash in your wallet, the funds in your bank account or the credit limit on your credit card. 

If the gift card came from someone you do business with, e.g. a supplier or customer, the answer will be different. 

Thanks, Hal_Al.

[Edited 3.7.2018 | 01:19 pm]

Hi,

What if I purchased discounted giftcards and use it to purchase items for business supplies or to ship out to other customers. Would the expense be the amount paid for the discounted giftcard? Thank you!

Assuming this is a business you report on SCH C as a part of your personal tax return, you can deduct "either" the cost of the cards, or what you paid for the business stuff with the cards. But not both. That would be double-dipping.