Science fairs have been around for decades, yet their critics question the extent to which parent involvement shapes students' investigations and creates inequitable experiences. Parent involvement in the science fair has been viewed as objectionable by parents themselves. However, research has shown that parent support can play a vital role in student learning. This article describes the results of research that explored the role of parents in middle school science fairs. Data from parent surveys and interviews, teacher interviews, and student focus groups were gathered from 21 schools across the U.S. (prepandemic) to examine patterns in parents' involvement in science fairs, including the roles parents play and whether involvement varied by parental characteristics. Findings show that parents' income and education affected their level and type of involvement, as did certain features of the science fair itself. Our findings have important implications for the structures of and equity in school-based science fairs.