Chinese as a world language has gained popularity in US K-12 education over the past two decades. However, little attention has been paid to diverse populations in Chinese language classrooms and how the students' diverse cultural and linguistic backgrounds influence their experiences in Chinese programs. This article presents a research synthesis that examines cultural and linguistic diversity in US K-12 Chinese language education research. It reveals the tendency of the field to oversimplify culturally and linguistically diverse (CLD) students into dichotomous groups (i.e., Chinese speaking vs. English speaking) and the inequitable representation of CLD populations as well as the underrepresentation of their experiences in the curriculum. The findings suggest that there is a need for the Chinese language education field to engage in critical conversations on diversity, and to make Chinese language teaching more culturally relevant and sustainable to the diverse populations it serves.