Although many girls may call themselves tomboys, little is known about the consequences of these self-perceptions. Seventy-six 5- to 13-year-old girls were interviewed and asked to identify their tomboy status (35 traditional girls, 20 tomboys, and 21 “in-betweens”). Tomboyism was associated with potentially negative gender identification (i.e., feeling less like a typical girl and less content with their gender), but more egalitarian perceptions of others (i.e., lower intergroup biases and greater acceptance of others’ gender-norm transgressions). To further develop the foundational tomboy literature, we first established that tomboyism was associated with more male-typical play preferences, examined the developmental course of tomboyism, and how girls describe this identity. Implications for theories of gender development are discussed.