There are many more, surely, but my aim with this list is not to show you every online shop that sells fabric, but rather the ones that I love to purchase from, judging by my own experience. These are the ones I recommend! 
Denmark
UK
USA
- Above All Fabric
- Banberry Place
- Fabric Hound
- Fabricworm
- Fabric.com
- Fat Quarter Shop
- Girl Charlee Fabrics
- Sew, Mama, Sew!
- Superbuzzy
- The Fabric Fairy
Sweden
- MinaNamnBand.se (woven labels)
Isn’t it expensive to order from the US?
No. Fabric prices are much lower on comparable qualities than in Denmark, and shipping is reasonable. At many fabric stores, if you order a maximum of 5 yards (1 yard = 91,44 cm), the fabric can be fitted in a flat rate envelope that ships for approximately $15.
If you are Danish, and you want more information on what happens, if you do your shopping outside of EU, you can find that here (DK). Go here (DK) to calculate what you will be paying besides the value of your order (if you are purchasing fabric, choose the category “Beklædning/Tøj”). When you do your shopping inside EU, fx. in Sweden or the UK, no extra charge will be added in general, however prices and shipping tend to be a bit steeper.
I have done a lot of fabric shopping online, especially in the US which of course is outside of EU. I have never had any problems with it, all shipments have arrived as planned, and in general I just find it brilliant, mainly due to the huge selection and very reasonable prices compared to the Danish market.
What if they don’t ship to Denmark?
If you would like to purchase something from a shop that ships only to the US, there are services that provide you with an American address, and forward your shipment at very reasonable rates. Check out fx. ShopUSA or Borderlinx.
If you would like to know more, or if you have specific questions, I would be happy to help. Please use the contact page to get in touch.