Neck circumference is quick and simple to measure and thus an attractive proxy of neck strength, a putative mechanism underlying risk of sport-related concussion (SRC). Research, however, is limited on the relationship of neck circumference to SRC. Our study examined differences in neck circumference based on sex, concussion history, concussions experienced subsequent to college entry, and participation in sports with high versus low risk for contact. Neck circumference was measured in incoming NCAA Division I athletes (N = 324) from a large northeastern university during athlete pre-participation physicals. Sex, sport team, and self-reported concussion history were obtained from retrospective pre-participation questionnaires and medical chart review. Concussion diagnoses during college were collected subsequent to neck measurements from medical chart review. Proportional neck circumference (normalized by body mass index) was computed. Each sport was categorized as involving high or low risk of contact (as a proxy of risk for injury). Sex differences in neck circumference and proportional neck circumference were assessed. Differences in neck circumference and proportional neck circumference were also characterized by contact risk and SRC history (with biological sex included as a covariate). Differences in neck circumference and proportional neck circumference were explored among those who did versus did not experience subsequent SRC diagnosis. Males had significantly larger neck circumference and proportional neck circumference than females. Neck circumference and proportional neck circumference were not related to SRC history or subsequent SRC. Neck circumference is a quick and simple measure; however, even when considered in proportion to body mass, it was unrelated to SRC. Future studies are needed to assess whether this is due to a lack of relationship between the neck and injury or limitations in circumference as a proxy measure of cervical spine characteristics and biomechanics.