Do all cherries have a pit?

Yes, most cherries have a pit, which is the hard seed inside the fruit. However, there are some varieties known as "sweet cherries" that are typically consumed fresh, and some "sour cherries" used in cooking and baking, both of which contain pits. There are also pitless cherry varieties available, but they are less common. Generally, when referring to cherries, it's safe to assume they have a pit.