Background: Mercury, particularly in its methylmercury form, significantly affects neurological and developmental functions. In Gyeongsangbuk-do, Republic of Korea, blood mercury levels are elevated due to high fish consumption, especially shark meat. Vulnerable groups, such as pregnant women, are at increased risk as methylmercury can cross the placenta and accumulate in breast milk. This study aimed to investigate the risks of mercury exposure from shark meat consumption among young and middle-aged women in Gyeongsangbuk-do. Methods: The data of women aged 19–55 years from the 2018 Gyeongsangbuk-do Community Health Survey were included. Survey questions focused on frequency and amount of shark meat consumption, as well as pregnancy status, recent childbirth, and breastfeeding status. The Complex Sample Analysis was used to determine the prevalence and risk of overconsumption. Weekly mercury intake was calculated for respondents who reported their body weight, and the population size exceeding Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) and Ministry of Food and Drug Safety (MFDS)’s threshold was estimated. Results: Regions where the consumption rate of shark meat exceeds the average for Gyeongsangbuk-do are found to be distributed in the southeastern part of the province. Population estimates revealed that approximately 9,895 women aged 19–55, including 255 who had breastfed in the past year, consumed shark meat exceeding the recommended intake. Based on the maximum recorded mercury concentration (8.93 μg/g), an estimated 2,645 women surpassed the JECFA’s mercury exposure threshold, while 845 exceeded the MFDS’s threshold. Conclusions In young and middle-aged women of Gyeongsangbuk-do, approximately 7.1% exceed the single intake limit, while up to 1.9% exceed the JECFA’s provisional tolerable weekly intake (PTWI) and 0.6% exceed the MFDS’s PTWI, suggesting considerable risk that warrants monitoring and guidance. More stringent advisory measures regarding shark meat consumption and updated standards on mercury concentration in shark meat are essential for young and middle-aged women in the province.