Put cream cheese in a large mixing bowl. Beat until smooth and fluffy.
Add condensed milk and mix until smooth.
Stir in cherry pie filling and drained pineapple.
Fold in Cool Whip until mostly uniform.
Chill for at least two hours to firm up before serving.
Notes
You can try using different flavors of pie filling. Strawberry or blueberry would also be delicious. You can spread the mixture in a 9x13-inch pan to help it firm up faster, or spoon it into individual bowls and chill. If you like nuts in fluff recipes, fold in ½ cup chopped pecans.