While tremendous progress has been made on attaining HIV treatment goals (95-95-95), children’s viral load suppression remains a challenge particularly among the orphans and vulnerable groups. In Sub Saharan Africa, there is limited evidence of specific interventions in orphans and vulnerable children (OVC) programs to support children and adolescents living with HIV (CALHIV) to attain durable viral load suppression. Through a large OVC cohort, the study sought to identify correlates of optimal viral load suppression among CALHIV in the Kenya OVC program. This cross-sectional study utilized data on CALHIV below the age of 18 years who were enrolled in the OVC program and actively receiving HIV care and treatment services from ART clinics across Kenya and with documented VL results between October 2019 and September 2020. To obtain a nationally representative sample, data was retrieved from USAID implementing partners’ databases across the country. Association between selected variables and VL suppression (outcome of interest) were assessed using a multivariate mixed effect logistic regression model, using glmer function in the LME4 package in R. Factors associated with VL suppression included child’s education status (aOR = 1.33; 95% CI: 1.07, 1.65), membership of a psychosocial support group (aOR = 1.258; 95% CI: 1.15, 1.38), and membership of a voluntary savings and lending association (VSLA) (aOR = 1.226; 95% CI: 1.129, 1.33). In addition, child’s sex (aOR = 0.88; 95% CI: 0.83, 0.94), caregiver sex (aOR = 0.909; 95% CI: 0.839, 0.997) and “high” status for caregiver household vulnerability (aOR = 0.81; 95% CI: 0.71, 0.924), had an inverse relationship with VL suppression. CALHIV characteristics including child’s sex, child’s education status (whether currently active in school or inactive) and child’s membership in a psychosocial support group were key determinants of VL suppression. Similarly, caregiver sex and membership in a voluntary savings and lending association also influence VL suppression.