The purpose of this study was to evaluate the midfoot longitudinal arch height and correlate it with active hip external rotation (ER) in dancers during static postures and technical steps of classical ballet (i.e., first position, demi-plié, battement fondu à la seconde, pas jeté à la seconde, and grand jeté à la seconde). A 3D motion analysis system was used for kinematic analysis. The arch height was significantly reduced during the battement fondu à la seconde, pas jeté à la seconde, and grand jeté à la seconde when compared to standing (p = 0.000 for all comparisons), first position (p = 0.000, p = 0.000, and p = 0.001, respectively) and demi-plié (p = 0.015, p = 0.003, and p = 0.006, respectively). No significant correlation was found between arch height and active hip external rotation (p > 0.05). Hence, active hip external rotation does not seem to be related to midfoot pronation in this sample. Other factors, such as intrinsic and extrinsic foot muscle strength, may be related to the midfoot arch height. These findings contribute to a better understanding of ballet steps, but future studies are required to clarify this topic completely.