We examined the role of parental support to children's sympathy, moral emotion attribution, and moral reasoning trajectories in a three‐wave longitudinal study of Swiss children at 6 years of age (N = 175; Time 1), 7 years of age (Time 2), and 9 years of age (Time 3). Sympathy was assessed with self‐report measures. Moral emotion attributions and moral reasoning were measured with children's responses to hypothetical moral transgressions. Parental support was assessed at all assessment points with primary caregiver and child reports. Three trajectory classes of sympathy were identified: high‐stable, average‐increasing, and low‐stable. Moral emotion attributions exhibited high‐stable, increasing, and decreasing trajectories. Moral reasoning displayed high‐stable, increasing, and low‐stable trajectories. Children who were in the high‐stable sympathy group had higher self‐reported support than children in the increasing and low‐stable trajectory groups. Children who were in the high‐stable moral emotion attribution group or the high‐stable moral reasoning group had higher primary caregiver‐reported support than children in the corresponding increasing trajectory groups. Furthermore, children who were members of the high‐stable group in all three moral development variables (i.e., sympathy, moral emotion attribution, and moral reasoning) displayed higher levels of self‐reported parental support than children who were not.