Background: The shape of the hairline is very important in a person’s identity and in determining the impression they make. Reports on the morphology of a normal hairline are still scarce. Differences in the shape of male and female hairlines in Japanese subjects are discussed in this study. Methods: A questionnaire about hairline type, the presence or absence of a widow’s peak, and measurement of the width and height of the forehead was given to 456 healthy subjects, and their responses were recorded. Results: Percentages of frontal hairline types were found to be linear (women 36.1%, men 45.9%), triangular (7.2%, 0.82%), round (38.5%, 10.7%), and M- shaped (18.2%, 42.6%). Temporal hairline types: inverted triangle (20.3%, 65.6%), inverted round (27.8%, 17.2%), straight (24.8%, 10.6%), and convex (27.2%, 6.6%). The incidence of a widow’s peak was 29.6% in women and 32.8% in men. The mean length of the mid-frontal line was 6.2 cm in women and 6.65 cm in men. Conclusions: Regarding the hairline morphology of the frontal view, two types (linear and M-shaped) accounted for 88.5% of men. In women, linear accounted for 36.1%, being relatively high, but lower than the frequency in men. Round accounted for 38.5%, being the highest. Regarding the temporal hairline, a hairless region (inverted triangle and inverted round) was noted in 82.8% of men. In women, a hairless region was present in 48.1% and was absent (straight and convex) in 51.9%. A temporal hairline with a hairless region was noted in the majority of men, whereas it was absent in slightly more cases in women.