Student-teacher relationship quality (STRQ) influences a variety of student outcomes, including academic, social, and behavioral functioning (McGrath & Van Bergen, 2015). Less is known about the importance of STRQ for preschool students with disabilities. Many studies are conducted with school-aged, typically developing students (Ansari et al., 2020; Hamre & Pianta, 2001), despite recognition that STRQ may be especially meaningful for young, vulnerable populations (Hajovsky et al., 2017; Sabol & Pianta, 2012). Among studies investigating the importance of STRQ for students with disabilities, most research investigates the connection between student background variables and STRQ, rather than how STRQ may influence other associations (Zendarski et al., 2020). In addition, studies tend to include students with specific disabilities and small sample sizes (e.g., Blacher et al., 2014; Eisenhower et al., 2007), which can be difficult to generalize. To address these gaps, the Family and Child Experiences Survey (FACES 2009), a nationally representative data set, was used in the present study to examine the following for preschool students with disabilities and delays: 1) the association between student-teacher relationship quality (STRQ) and student's kindergarten academic outcomes, 2) the association between Head Start student, teacher, classroom (HS-STC) variables and student kindergarten academic outcomes while accounting for student background variables, and 3) the role of STRQ as a moderator between HS-STC variables and student kindergarten academic outcomes while accounting for student background variables. STRQ was measured using the Classroom Assessment Scoring System (CLASS; Pianta et al., 2008). Structural equation modeling using latent-factor moderation analysis was completed using Mplus Version 8.6 software (Muthen & Muthen, 1998-2017). Study results suggest that STRQ moderated the association between student gender and kindergarten reading outcomes, such that male students with disabilities and delays performed better on reading outcomes when STRQ in Head Start was strong. Teacher experience and Head Start reading outcomes were significantly associated with kindergarten reading outcomes. Specifically, better kindergarten reading outcomes were associated with students who had Head Start teachers with less experience and students who performed better on preschool reading outcomes. Study limitations and implications for future research and practice are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]