Essentialism is the tendency to believe members of a category share an underlying essence that predicts their behavior. The majority of research on essentialism has focused on race and gender, and thus less is known about the essentialism of other categories such as ethnicity and socioeconomic status (SES). Using a predominantly Hispanic, low-income sample, we examined whether adults essentialize ethnicity and SES and whether their essentialism level is shaped by their own ethnicity (Hispanic, non-Hispanic) and SES background. Results suggested that participants essentialized ethnicity to a high level and essentialized SES to a limited degree. Contrary to our prediction, adults’ own ethnicity and SES did not affect their essentialism of ethnicity and SES respectively. However, Hispanic participants essentialized SES more than non-Hispanic participants. Future research on a broader range of Hispanic samples is needed to test the underlying mechanism and implications of such belief patterns.