<p>Children with bilateral cochlear implants (BCIs) remain vulnerable to developmental challenges relative to typically developing peers (TD), even when access to sound through acoustic or amplified hearing is achieved within the first year of life. This study evaluated contributions of hearing history, etiology, vestibular/balance function, and socioeconomic marginalization to language, working memory, and academic outcomes. Ninety-six children aged 4.65–17.85 years participated: 66 with BCIs (mean [SD] age, 11.54 [3.57]) and 30 typically developing (TD) peers (mean [SD], 11.69 [2.68]). Standardized assessments included the CELF, Dot Matrix, Corsi Block, Digit Span, and WIAT-III subtests. Regression and principal component analysis (PCA) identified predictors of developmental outcomes. Children with BCIs scored significantly lower than TD peers in language (<i>p</i> = 0.003), visuospatial working memory (<i>p</i> = 0.001), math (<i>p</i> &lt; 0.001), and word reading (<i>p</i> = 0.048). PCA identified four components: hearing loss history, auditory experience/resources, social marginalization, and vestibular/balance function. Only auditory experience predicted developmental outcomes across domains (<i>p’s </i>&lt; 0.05). Vestibular and balance function were impaired in the BCI group (<i>p</i> &lt; 0.001) but did not predict language, working memory, or academic scores. Deficits were most pronounced in children with congenital cytomegalovirus, cochleovestibular anomalies, and genetic hearing loss. Results emphasize the importance of sustained early auditory access together with etiology-informed, multidisciplinary support to optimize developmental outcomes in children with BCIs.</p>