We conducted an overview of reviews to determine the effects of naturalistic developmental behavioral interventions (NDBIs; Schreibman et al. (2015) J Autism Dev Disorders 45:2411-2428) on children with autism spectrum disorder under 8 years old. We conducted an electronic database search of Academic Search Premier, CINHAL, ERIC, Medline, and APA PsycINFO in October 2022 and August 2023 and utilized snowball methods to locate relevant reviews of NDBI. We included reviews meeting the following inclusion criteria: (1) review included a meta-analytic synthesis for at least one child outcome; (2) primary studies examined a NDBI; (3) primary studies included children with ASD with a mean pre-treatment age under eight years; (4) primary studies were conducted using a two-group comparison design; and (5) review was published in English. We extracted data on characteristics of the review, participant characteristics from the primary studies, intervention characteristics, and assessed the risk of bias of the included reviews. We conducted a narrative synthesis across outcomes reported in the included reviews. We included five reviews from six reports in this overview. Two reviews included studies that examined the Early Start Denver Model, two reviews included studies that examined the Pivotal Response Treatment, and one review included studies examining NDBIs collectively. We found positive effects of NDBIs on child's communication/language, cognition, and adaptive behavior. We found mixed effects for NDBIs on autism symptomatology and restricted and repetitive behaviors. Examination of moderator analyses reported in the included reviews suggested variables influencing the effects of NDBIs included proximity of outcome to intervention, boundedness of outcome to intervention, and study location. As shown in this overview, positive effects of NDBI for young children with ASD are supported by meta-analytic evidence. While the overall findings for NDBI across reviews are positive, the findings on specific outcomes and influential variables moderating the effects of NDBI are inconsistent. Additional evidence from randomized controlled trials and future meta-analyses are needed to strengthen our knowledge of the effects of NDBI for young children with ASD.