Alanna of Trebond from the Song of the Lioness series by Tamora PierceRead about the other entries on the list.
Alanna’s skills as a knight come from years of hard training, working her way from an awkward young squire to the mythical figure of the Lioness Rampant. Every scrap of fighting in this red-headed heroine is learned and hard-earned. Alanna also holds a major place among my favorite heroines because she is the first heroine I remember reading about who dressed as a boy to go looking for a better destiny than the one society has given her. But, looking back, it’s also an awfully impulsive decision for a ruse that she has to spend years keeping up. When Alanna and her brother decide swap places, her twin winds up happily learning magic with no risk, while Alanna is left scrambling to figure out how to hide her true identity as puberty kicks in around a whole bunch of boys who are not quite so clueless that a few of them aren’t going to notice it happening.
Alanna: the First Adventure is among Gail Carriger's top five books where girls disguise themselves as boys.
--Marshal Zeringue