I don't know about in the past, though, I do know that one has closed down in the last year (the one on the walkway across from Tom Sawyer Island.
The current ones are across from Aloha Isle, Big Thunder (past the line entrance), Space Mountain (next to the bathrooms), on the pathway behind Goofini, overlooking the train and Speedway, and off to the right just as you exit the castle and enter Fantasyland.
So, Magic Kingdom has 5.
At Epcot, there are 8. China, Italy, Japan. One on each side of the entrance to World Showcase. One at the International Gateway. One inbetween the Land and Imagination and another one near World of Energy.
Hollywood Studios has 5. One near Echo Lake, across from Indiana Jones. One off to the side of the Great Movie Ride, near the Commessary. One near the big Coke Bottle and the old entrance to the Backlot Tour. One in Fairfax Fare, near the entrance to the RnR pavilion. One out in the Fantasmic complex.
Animal Kingdom has 5 as well. One is near the main entrance, one right before the bridge near Expedition Everest. One off to the side of the Dino Institute. One down a pathway near Pizzafari. And one out at Rafiki's Planet Watch.
Typhoon Lagoon boasts 3 of them. Blizzard Beach has 2. DTD also has several...though, I'm not sure how many.
Compare that to Disneyland.
Disneyland itself has 3. One near Big Thunder, one near the Matterhorn Bobsleds overlooking the lagoon, and one in New Orleans Square, near Haunted Mansion.
California adventure has 4. One across from Sourin', one down a path near the area where paradise pier and Grizzly Peak merge, one near Monster's Inc all the way in the back near the water tower, and one across from the Silly Symphony Swings.
There are also several littered throughout Downtown Disney. One that springs to mind is just outside of House of Blues. There's another one across from La Brea. I can't think of any others offhand, but I'm sure they exist.
For comparison...Disneyland Paris, it seems, has 10 smoking areas.