Preheat the oven to 400°F.
Arrange a rack in the top third of the oven and preheat. Line a rimmed baking sheet with parchment paper.
Make the meatball mixture: Place the ground chicken, breadcrumbs, pesto, egg, salt, and pepper in a large bowl. Mix lightly with a fork until just combined.
Form the meatballs: Form the meat mixture into 20 (about 1 1/2-inch) meatballs and place them on the prepared baking sheet, spacing them out evenly as you go.