Clean and oil the grill grates.
Using tongs, remove the peaches from the honey mixture and place them, cut sides down on the grill (reserve the honey mixture in the bottom of the bowl for serving). Cover and grill until the peaches are caramelized with nice grill marks, about 2-3 minutes.
Flip the peaches over. Cover and cook until grill marks form on the other side and the peaches are tender in the center, about 1-2 minutes longer, depending on the ripeness of the peaches (you can skip this step if the peaches are really ripe). Transfer to a platter or to plates and let cool slightly—you can serve them warm or at room temperature.