Background and Objectives: Folic acid (FA) is a necessary ingredient for numerous bodily activities including pregnancy. Because of this, women should have knowledge and awareness of the health benefits of FA supplementation. Thus, we aimed to investigate the level of knowledge on the importance of FA and determine associated factors for knowledge among female college students at King Saud University in Riyadh, Saudi Arabia. Material and Methods: We conducted a cross-sectional study using a questionnaire between January 2020 and February 2021 among female college students aged 17 to 26 years old. The questionnaire adapted with permission from Alnaami et al. included questions on the demographic profile of the participants as well as questions related to their knowledge and awareness of FA, FA supplementation, the importance of supplementation and their sources of knowledge of FA. Results: A total of 437 female undergraduate students participated in the study, 285 (65.2%) of whom were from the non-health colleges and 152 (34.8%) from the health colleges. The majority of participants were between ages 17 and 21 years old (n = 361, 82.6%). Half of the respondents were in their 3rd and 4th year of study (n = 122, 50.8%), 138 respondents (31.6%) were married, and 111 of these married women (80.4%) had children. There were 266 respondents (61.0%) who had heard and had knowledge of FA, 241 (55.3%) knew of FA timing of intake, 243 (55.7%) of FA duration of intake and 362 (83.0%) knew of the diseases prevented by FA supplementation. Linear regression analysis showed that being in the health college (B = 1.464, t = 11.37, p < 0.001, 95% CI = 1.211, 1.717) and a higher educational year level (B = 0.139, t = 2.442, p = 0.015, 95% CI = 0.027, 0.251) were the significant predictors of knowledge of FA. Conclusions: Knowledge of FA and FA supplementation was low at 61% considering that our study population were college students. Being enrolled in a health college and in a higher educational year level were significant positive correlates of higher knowledge of FA and FA supplementation. Despite this, there exists a gap of information regarding FA and FA supplementation particularly among single women and college educated women in the early years of their college life as well as those in non-health colleges.