In the current qualitative research study, we focused on understanding the ecological systems, contexts, behaviors, and strategies of parents (N = 435) advocating for their children with an intellectual and developmental disability diagnosis, specifically Down syndrome (DS). Based on the data analysis, parents of children with DS advocate for their children frequently, in a variety of settings, with different actions, attitudes, motivations, and outcomes. The most common settings where advocacy occurred were primarily school and healthcare systems. The goals of parents often included inclusiveness, equality, and acceptance, whereas a few parents reported advocating due to discrimination and judgment. Implications for further research and professional practice also are described.