Increasing school-based parental involvement—which has links to improved student outcomes like academic achievement—is a core area of focus in many preschool programs. Yet, little research to date has examined what the association is between attending preschool and school-based parental involvement in early elementary school. This study addresses this gap by drawing on nationally-representative data from the Early Childhood Longitudinal Study-Kindergarten Class of 2010 to 2011 (N = 18,174) to examine the association between preschool attendance and measures of school-based parental involvement in early elementary school. The findings reveal consistent positive associations between preschool attendance and school-based parental involvement. There is little evidence of variation in associations based on the type (e.g., private and Head Start) or location (e.g., center-based and school-based) of the preschool program. (author abstract)