Boyish Short Hair

Western Animation

 * Buttercup from The Powerpuff Girls has her hair in a stylized bob haircut. Her more feminine sisters Bubbles and Blossom wear Girlish Pigtails (though her hair is barely longer than Buttercups when down) and bone-straight Rapunzel Hair respectively. Buttercup is the tomboyish Blood Knight of the group.
 * Luna Loud of The Loud House sports a pixie cut, and she's among the more tomboyish of her sisters. To drive it home, before she got into rock and roll she had much longer hair as well. Likewise, her sister Lisa Loud dons a wig of a short, scruffy, unkempt bob cut (she went bald due to a science experiment gone wrong) and is among the other less traditionally feminine of the Loud sisters, being very stoic and into conducting science experiments involving things like explosions and poop.
 * Inverted with Pearl in Steven Universe. Pearl's hair doesn't even reach her shoulders, but she's the most feminine of the Crystal Gems.