Cut each peach in half along the crease, twist open, and remove the pit. Peel and slice. Cut slices in half to get roughly 2 cups of sliced peaches.
Bring sugar and water to a boil in a saucepan over medium-high heat. Boil until a syrup forms, about 3 minutes. Stir in peaches until coated. Bring syrup back to a light simmer, about 1 minute. Immediately remove from the heat and pour mixture into a bowl to cool, 15 to 20 minutes.
Use a slotted spoon to transfer peaches to a large bowl. Discard simple syrup or reserve for another use. Pour in heavy cream and stir to combine. Divide mixture between six serving glasses or bowls, cover with plastic wrap, and refrigerate until completely chilled and cream has absorbed all the peach flavor, at least 3 hours.