Yes, it's a sandwich. It just happens to also be the best kind.

of course it is mmmmmm.

It is the best type of sandwich. I had three last night. 

A sandwich is food inside of two similar objects, be it bread, bun, or pieces of fried chicken. Thus, the hamburger is a sandwich.

I recently got in a heated debate over a "veggie burger."

I'm in England and not obsessed with food, or comparatively knowledgeable in the area, but to me sandwiches are in slices of bread and burgers are in buns.

If I can make a ketchup sandwich, I'm sure you can make a burger sandwich.
 
Burger + Fried Chicken + Another Burger = Heart Aorta Down

So I actually just got back from my local pub and eatery and noticed something interesting. 
  
There's no burger in the sandwich section of the menu. After a good amount of searching, turns out, the burgers are found under the burger section! As far as I can remember, it seemed like every restaurant that I have ever been to shared that same grouping.
 
Seems like a pretty clear answer to me.

a hamburger is a sandwich with cooked meat.

Meatballs = Ground meat 
Burger patties = Ground meat 
Wouldn't that mean a meatball sandwich is a hamburger?

it is a sandwich. where are the poll results?

If a Lion is a cat then a Hamburger is a sandwich. It shares the exact same qualities as a lion: Regal, Noble, and Delicious. 

yes but not really

Me at mcds drivethrough: "hi, Big mac combo and a quarter pounder on the side, please" 
mcds lady at drivethrough: "So just the sandwich then?" 

" Me at mcds drivethrough: "hi, Big mac combo and a quarter pounder on the side, please" mcds lady at drivethrough: "So just the sandwich then?"  "

I agree that by definition, yes it is. But, that also begs the question does anything become a sandwich if you put it between two slices of bread, like people, a toy car, or an idea...

yes. its on bread... its a manly sandwich

A hamburger is not a sandwich. Not a pure sandwich anyway

is a hambog a sandwich?

of course it's a sandwich, anything that involves putting edible stuff between 2 slices of bread is a sandwich.

" @onarum: A croque-monsieur is not a sandwhich. Your argument is invalid sir ! Good day sir ! "

So I just discovered Cheeseburger Doritos - they're made with real beef flavoring.  Do they count as a cheeseburger?  Or just something that tastes like a burger but isn't up to par with the real deal?

Well; Mc. Donalds think that is the case. And as they make quite a couple of sandwiches each year, I would go for a shaky yes. 

If sandwiches is anything between two pieces of bread, isn't a loaf of sliced bread is essentially a "bread sandwich"? It's lots of bread sandwiched between two other pieces of bread.
 

BEHOLD.  THE BREAD SANDWICH.

Oh i love this thread, 
 
What i want to know is that if anything between two slices of bread is a sandwich then there are some horrific horrific creations that can be made... i look forward to this.

Guys! I finally have the answer to this question!!! It's "yes!!!"

I'm with team yes.

New Theory: 
 
Burgers require burger buns and a patty of something. The term overrules normal sandwich categorizing conventions, hence "burgers" are something in their own right, rather than merely being a subset of the sandwich family. 
 
DIAGRAM:

i would think they are sandwiches, but they are their own type of sandwich? idk it sounds better in my head

This should be the most viewed thread on GB.

If they call it a sandwich, I call it a sandwich. 
 
Also, it's meat and condiments between two pieces of bread. If the hold-up is over sliced versus ground meat, then is bologna not a viable sandwich? No. It's a damn sandwich.

sandwhich is the genus, hamburger is the species

To me a, burger is merely a sandwich that has a meat patty instead. Boiled down a sandwich really is just stuff between some bread. 

Hamburgers are totally sandwiches. They are simply the best kind of sandwich. That's the sub-category: Best.

I think the underlying mechanics are the same and that a Hamburger is, in fact, a sandwich.  though, a sandwich may not be a hamburger.

beef is what makes it a hamburger, sandwiches with beef....never existed

Hamburgers are too specialized to be lumped in with "sandwiches".

" beef is what makes it a hamburger, sandwiches with beef....never existed "

If it's got two pieces of bread and something in-between, it's a sandwich, yo. 
 
Not sure what that makes the Double Down, though.

" Not sure what that makes the Double Down, though. "

Well, I consider a meatball sub to be a sandwich yet not hamburgers. I think the secret lies with the patty since I've used hamburger buns to make sandwiches and I've never called them burgers. Then again, where would meatball subs fit in this? They are made from cooked ground beef as well. 
 
After much consideration, I can only conclude that a hamburger was a sandwich that became so incredibly popular that it outgrew the sandwich family and created it's own distinct category. Thus the answer would be no.

YES, now stop arguing about it.

The real question is: what is a Patty Melt considered?