Individuals rely on Theory of Mind (ToM) to represent themselves, others, and socio-cultural norms. Distinctive Western and Eastern developmental patterns of ToM have been reported in monocultural children. Relatively little is known about bicultural children, especially those children who grow up in two conflicting and unbalanced cultures. We hypothesized that the development of ToM in these bicultural preschoolers would follow the pattern of the dominant culture. To examine this hypothesis, we recruited English-speaking Chinese Singaporean preschoolers. In Study 1, we tested 3- to 5-year-olds (N = 120) with 5 ToM tasks, including diverse desires, diverse beliefs, knowledge access, and false belief, as well as a vocabulary task. In Study 2, we tested 5-year-olds (N = 30) with a picture-choice version of these ToM tasks. Both studies supported our hypothesis by revealing that the development of ToM in these bicultural children followed the pattern of the dominant culture. Additionally, we found that 5-year-old bicultural children are still developing false belief, and their verbal ability correlated with their ToM.