Body mass index (BMI) is an indicator to detect weight category and known to influence the academic achievements of students. The present study assesses the association of BMI, physical activity with academic performance among undergraduate female students of health colleges, King Khalid University (KKU). Responses from 379 participants were analyzed in the study. Data collection was done by administering an online questionnaire using the university website portal. The questionnaire consists of two sections: the first section includes demographic information along with cumulative Grade point average (GPA) and another section rated student’s physical activity. A high frequency of respondents (53.6%) ranged within the normal BMI category. For academic performance, the majority (79.9%) of students reported high GPA scores with a mean of 4.28 ± 0.41. Upon correlation, academic performance was found negatively correlated with BMI at 0.0001 level of significance, and insignificantly correlated with physical activity. The present study observed that more than half of the respondents had normal BMI. An inverse relationship was observed between BMI and academic performance, showing participants within the normal BMI category achieved significantly higher GPA. In contrast, physical activity directly influenced the academic performance of the subjects. Therefore, the study suggests to enact counselling centers, health clubs in universities urging the students to adopt regular exercise and healthy lifestyle which could prepare them in achieving future endeavors.