This article serves as an introduction to the Special Issue on "Decolonizing and Diversifying Research in Cognitive Development." The Special Issue comprises six articles: two articles are empirical articles that focus on executive function development in under-represented environments, two articles address barriers pathways toward behavioral change in advancing toward diversification and decolonization; and two articles focus on reconciling sampling and reporting practices with the scientific goal of generalizability. Though different lenses, each article identifies important practices and considerations for broadening the study of cognitive development to faithfully represent children's diverse environments and trajectories via developing methods and practices "in situ" and sampling judiciously across diverse settings. The series culminates in a commentary via Bard and Keller, who discuss each article and articulate future pathways toward decolonization and diversification.