I get asked this all the time. Someone's writing copy for a bag company, or they're putting together a product listing, or they just got into an argument with their spouse about the "right" way to spell it. Short answer: both work. Long answer: there's a town in Belgium you've never heard of, and that town is the reason we're having this conversation.
The Town Nobody Visits
Duffel sits about 15 kilometers outside Antwerp. Population around 17,000. The town has a railway station that opened in 1836. There's a statue of a coat on a traffic roundabout. That's about it for tourist attractions.
The cloth production started in the 15th century, maybe earlier. Some sources say the 11th century, which seems like a stretch, but the records from medieval Flanders aren't exactly complete. What we know is that by the 1600s, this town was shipping heavy woolen fabric across Europe. The stuff was thick, coarse, had a napped surface. Sailors used it to patch sails. The Spanish and Portuguese bought a lot of it.
Here's the thing about the town: the cloth industry died out by the 1800s. English manufacturers figured out how to make the same fabric cheaper. The last duffel weavers in Duffel were gone before anyone alive today was born. The town archivist apparently gets calls from people around the world asking where the duffel coat factory is located. He has to explain there never was one. The coat got developed in Britain, using fabric that originated from Duffel's design, long after Duffel stopped making the stuff.
So Which Spelling
The town is spelled Duffel. One F, E-L at the end. The word entered English in the 1670s as "duffel" because that's what the Dutch called it. The Oxford English Dictionary traces it to 1677.
"Duffle" showed up later. The English started pronouncing it their own way, and the spelling shifted to match. By the time the British Royal Navy was issuing duffel coats to sailors in the late 1800s, both spellings were floating around.
American English stuck with "duffel." British English went with "duffle." If you're writing for an American audience, use duffel. If you're writing for a British audience, use duffle. If you're writing for a global audience, pick one and stay consistent. Your spell-checker might flag one or the other depending on what language settings you have.
I looked at Google search data. "Duffel bag" gets searched about ten times more than "duffle bag" worldwide. That doesn't make it more correct. It just means more people type it that way.
The E.E. Cummings Thing
The first written record of "duffel bag" in English comes from a letter by E.E. Cummings. He was working as an ambulance driver in France during World War I, part of the Norton-Harjes Ambulance Corps. In 1917, he wrote home that he "had a duffel bag, chuck full."
Cummings is the guy who refused to capitalize his name and wrote poems that looked like they went through a blender. He got arrested by the French military on suspicion of espionage a few months after writing that letter. His father had to write to President Wilson to get him released. He turned the whole prison experience into a novel called The Enormous Room.
The bags the soldiers used back then were short, maybe 18 inches, with brass eyelets and rope closures. They were terrible for carrying heavy loads. A lot of soldiers just left them in the trenches. The military didn't figure out how to make a decent duffel until 1943, when they stretched the design longer and added a proper shoulder strap.
The Coat
There's also a duffel coat. Same origin story. Toggle closures, big hood, made from that heavy woolen fabric. The British Royal Navy used them on Atlantic convoys during World War II. Field Marshal Montgomery wore one. Paddington Bear wears a blue one.
The coat had a moment in the 1950s and 1960s. Then it became associated with academics and lefty politicians. In 1981, Michael Foot, the leader of the Labour Party, showed up to an Armistice Day ceremony wearing a duffel coat. The press destroyed him for it. Called it scruffy, disrespectful. The coat never really recovered from that.
You can spell it either way. "Duffel coat" or "duffle coat." Same rules as the bag.
What I Actually Think
Use "duffel" if you want to be technically correct about the Belgian origin. Use "duffle" if that's what looks right to you. Nobody is going to refuse to buy your bag because you spelled it wrong. The people who care about this distinction are mostly copywriters and the occasional etymology nerd.
The town of Duffel put up that coat statue in 2007. A local businessman named Frans Vermeulen commissioned it. It stood outside his company office for years before the municipality agreed to put it somewhere public. They stuck it on a roundabout. I don't know what that says about how Duffel feels about being famous for a coat and a bag, but it probably says something.
