Gender is one of the most fraught issues of our age: ideologies continue to be mobilised by the far-right, and trans lives are increasingly villainised and targeted in the political arena. But what is gender? Where did the concept itself come from, and where might it go? In this essential work, leading trans scholar Susan Stryker invites readers on her life-long quest to uncover what gender means and does. From nineteenth-century phrenology to present-day anti-trans conspiracy theorists, Stryker finds surprising places to tune in to the origins, idiosyncrasies, and generative possibilities of the gender concept. Woven in are stories drawn from her lifetime as a path-breaking historian, filmmaker, activist, and founding figure of transgender studies. Deeply researched and poignant, Changing Gender is a clarion call for new possibilities of expression and identity, and for trans justice in the interest of collective survival.