Alton Brown and an Elvis impersonator called it a custard pie.
cooking.stackexchange.com/users/40/Tesserex
In my opinion, cakes rise, pies have crusts that are filled (and do not rise).
By those loose definitions, I would consider it a pie.
edit:
Wikipedia says it's neither.
Many types of cheesecake are essentially custards, which can lead a novice baker to overcook them, expecting them to behave like true cakes.
cooking.stackexchange.com/users/1236/stephennmcdonald
Cake Straight sides No fruit (except as an optional topping) Holds its shape when sliced Pie Separate crust Not frosted Doesn't rise (except temporarily while baking)
No crumbs Conclusion
Who cares, let's just have some cheesecake. :-)
cooking.stackexchange.com/users/2569/Marti
It is neither; it is a unique dessert category, the cheesecake.
It has structural similarities with pies (a custard based body, a mechanically separate crust).
However, in the US for whatever reason, it is referred to as a cheesecake
(you will note that rarely will someone say, for example "I will bring a cake" and show up with a cheesecake).
The unique label doesn't mean that it is a cake in the same way that a pound cake or an angel food cake are, but we have lots of inconsistent labels.
cooking.stackexchange.com/users/14401/SAJ14SAJ
While it has texture and body of cake, I would argue that cheesecake has more pie-like qualities.
It has a discrete crust.
It is more a filling than a batter.
It does not need to be frosted.
My vote is "pie."
cooking.stackexchange.com/users/2832/Sean Hart
Cheesecake is a filling and flavor, like chocolate.
You can make it into a pie with crust, you can add it as a filling between layers of cake, or even have an entire cheesecake round as a layer of the cake.
Cheesecake does not require a crust for proper preparation.
In the US Cheesecake is most often served as a pie with a crust on the bottom, so many will claim it is a pie, but there is nothing about cheesecake itself that makes it a pie, any more than pudding or mouse is a pie merely because they can be served as pies.
cooking.stackexchange.com/users/10979/Adam Davis
My mother made several cheesecakes and cheese pies as I was growing up; there is a distinct difference.
A simple cheesecake and a simple cheese pie have, more or less,
the same basic filling: everyone knows the flavor/taste.
But even these two have a subtle difference (and an obvious one).
Obvious: The cheesecake stands taller and is square on the sides (as mentioned elsewhere here).
Subtle: A simple cheese pie has more of a custardy texture, whereas a cheesecake is very rich and thick.
Beyond that, a cheesecake can be made into many more varieties that a cheese pie typically does not: ice cream cheesecakes, mocha swirl cheesecakes...
Cheese pies do not have the body to allow for some of the structures that a cheesecake can offer.
This is because cheesecakes are best made with a springform pan, which allows for many different varieties.
Please peruse this book if you get the chance.
It was my mother's bible as I grew up, and I use it today.
cooking.stackexchange.com/users/28767/Jason P Sallinger
Is cheesecake technically a pie or a cake?  I'm curious as to why. Are there solid definitions of what makes a dessert a cake or a pie?
Is cheesecake a cake or a pie?
cooking.stackexchange.com
<baking><pie><cake><cheesecake>
cooking.stackexchange.com/questions/8352
cooking.stackexchange.com/users/2962/Paul Biggar
A cake has straight sides, no fruit and holds its shape when sliced, while a pie has a separate crust, is not frosted and doesn't rise. Cheesecake is really neither of the two, and can be considered its own category of dessert as well as a flavour like chocolate. Cheesecakes are neither a cake or a pie. They are a category of their own.
It is a unique category. It is also a filling and a flavour. Cakes rise and pies have a crust.