Research Findings: This article presents a naturalistic investigation of the patterns of formal education, early childhood education training, and mentoring of a diverse group of urban early childhood educators participating in the Los Angeles: Exploring Children's Early Learning Settings (LA ExCELS) study. A total of 103 preschool teachers and family child care providers serving primarily low-income 3- and 4-year-old children in Los Angeles County provided data on their education, training, and beliefs about teaching. This sample worked in public center-based preschool programs including Head Start classrooms and state preschool classrooms (n = 42), private nonprofit preschools including community-based organizations and faith-based preschools (n = 42), and licensed family child care homes (n = 19). This study used a person-centered approach to explore patterns of teacher preparation, sources of support, supervision, and mentoring across these 3 types of education settings and how these patterns are associated with early childhood educators' beliefs and practices. Findings suggest a set of linkages between type of early education setting, professional development, and supervision of teaching. Public preschools have the strongest mandates for formal professional development and typically less variation in levels of monitoring, whereas family child care providers on average have less formal education and more variability in their access to and use of other forms of training and mentorship. Four distinct patterns of formal education, child development training, and ongoing mentoring or support were identified among the educators in this study. Associations between professional development experiences and teachers' beliefs and practices suggest the importance of higher levels of formal training for enhancing the quality of teacher-child interactions. Practice or Policy: Implications of the findings for changing teacher behaviors are discussed with respect to the setting context. (Contains 9 tables.)