You can get it in Adventure Land in Magic Kingdom. It is like a pineapple ice cream, it's good but to be honest when I am at Disney there are so many other things I would rather eat
I love the Dole Whip float!! It is the pineapple soft serve ice cream with pineapple juice poured over it!! Delicious!! It is definitely one of the "have to have" items for my family while in WDW. We are at the Poly this year so I can have them all of the time! You have to try it at least once!!
We went to the Dole Plantation in Hawaii last year just as the cafe was closing. I was unable to try a Dole whip there, so it is on my to do list this May in WDW since we won't be back to Hawaii any time soon.
just a note--Dole whip is not actually ice cream, it's "soft serve" dessert made out of lots of things, but not ice cream.
That said, we love it. It's available at Aloha Isle counter service in Adventureland (near Swiss Family Tree House...only problem here is the seating area closest to Aloha Isle is actually the smoking area so be careful where you choose to sit!) You can get Dole whip in a dish, or as a float here.
Also available at Captain Cook's, which is the counter service restaurant located on the first floor of the main lodge at the the Polynesian Resort. At Captain Cook's there is no Dole Whip floats, it's just available in a dish.
Also, you can get Orange/ Swirl at MK, but Captain Cook's at Poly just has Pineapple/Vanilla/ Swirl. Plus, Captain Cook's is self-serve. I am tempted to put by head under the spicket and post a picture. I like pineapple- vanilla best.