A Hawaiian pizza, also known as pineapple pizza, is a pizza topped with pineapple, ham (or Canadian bacon/salame/etc), tomato sauce and cheese.
The dish tends to spark debate regarding the inclusion of pineapple on pizza.
Despite the name (which was actually inspired by the canned pineapple brand used by the pizza's inventor at the time), it was invented in Canada by the Greek immigrant Sotirios "Sam" Panopoulos.
This tag implicates pineapple_on_pizza (learn more).