This study examined the risk of low energy availability (LEA) and eating disorders among elite adolescent female athletes from a mixed-sport cohort and ballet dancers in Singapore, where the accelerated biological needs of adolescent growth and maturation overlap with the pursuit of sport/ballet excellence and high-stakes academic testing. All of these are competing demands for adequate fuelling and seeking timely treatment, which consequently affect the risk of LEA. Eighty-nine participants (41 athletes, 48 dancers; age 16.00 [3.00] years old) were screened for the risk of LEA and eating disorders using the Low Energy Availability in Females Questionnaire (LEAF-Q) and Brief Eating Disorder in Athletes Questionnaire (BEDA-Q), respectively. The main effects of athlete/ballet status and age (≤15 years old versus 15.1 years–18 years old) on LEAF-Q and BEDA-Q scores was be determined via Spearman’s correlation coefficient and linear regression analyses. The Mann–Whitney U test and Fisher’s exact test were used to compare the groups for the risk of LEA and ED. We observed that adolescent athletes and ballet dancers had a similar prevalence of being at risk of LEA (61.98% versus 54.17%, respectively, p = 0.529), with the risk of eating disorders absent in most of them. It appeared that the risk of LEA is likely of an unintentional nature in this study as the risk of ED was absent in 90.2% of the adolescent athletes/ballet dancers that were at risk of LEA. The age of the participants was significantly correlated with the risk of LEA, while the number of training hours was negatively correlated with the same factor. Age was also found to be negatively correlated with the number of training hours. The findings suggest that the risk of LEA in Singapore youth athletes and dancers are multifaceted, involving factors such as type of activity, age, and training hours. Targeted and tailored interventions and programmes are thus needed to promote adequate energy availability for optimal physical and psychological growth in sport and dance.