Science competitions are positively linked to students' science career pursuit and admission at top universities. The search for effective gender equity measures has become a priority as girls are less successful during science Olympiad team selection. Based on the expectancy-value model we performed latent profile analysis on a dataset of 445 Chemistry Olympiad participants (51% female, mean age 16.50 years). We characterized motivational profiles, predicted profile membership using the gender-science Implicit Association Test, gender, and socializers’ support, and examined how profile membership influenced performance. We identified four profiles distinguished by career motivation, interest, and domain identification: fearful pessimists, average participants, carefree participants, and worried optimists. The least successful group was associated with stronger gender-science stereotypes, less parental support, and the female gender. We discuss these findings in light of the importance of parental support and the diminishing effect of gender-science stereotypes on feelings of belonging for girls.