Neuroblastoma is a clinically heterogeneous pediatric malignancy of the developing sympathetic nervous system. Patients with high-risk disease have a 5-year survival rate of less than 50% and survival after relapse is extremely rare, urging novel clinical developments for these patients. Recent studies have uncovered the transcriptional networks that contribute to neuroblastoma heterogeneity and establish the adrenergic (ADRN) and mesenchymal (MES) subtypes. The overall goal of this dissertation was to profile the cell-surface landscapes of each neuroblastoma subtype and prioritize candidate subtype-specific proteins for preclinical development. We integrated transcriptomic and epigenomic datasets from patients and cell lines to identify candidate MES-specific, ADRN-specific, and pan-subtype targets. We show that AXL and other receptor tyrosine kinases (RTKs) are enriched in MES-dominant patient samples and neuroblastoma cell lines. We show MES-specific anti-tumor activity with an AXL-targeted antibody-drug conjugate (ADC), ADCT-601, and achieved a maintained complete response in treated animals. In ADRN-dominant neuroblastomas, we focused on the Notch ligand DLL3 as a candidate target. We found that DLL3 contributes to neuroblastoma fitness, possibly through activation of Notch signaling and upregulation of HES1. However, we discovered that DLL3 expression was heterogenous within ADRN-dominant patient-derived xenografts (PDX) and patient samples, and at a lower antigen density than other neuroendocrine tumors. Consequently, DLL3-targeted immunotherapy with the ADC Rovalpituzumab Tesirine (Rova-T) was active, but not curative, in PDX models. Finally, we propose B7-H3 as both a pan-neuroblastoma subtype and pan-cancer antigen. We show that B7-H3 is expressed across pediatric solid tumors including rhabdomyosarcoma, and osteosarcoma, and B7-H3 expression is stable across ADRN and MES neuroblastoma samples. Treatment of pediatric PDXs with a B7-H3-specific ADC resulted in complete and durable responses. Altogether, our work underscores the importance of considering tumor heterogeneity in preclinical drug discovery and our data demonstrate early preclinical activity with several subtype-specific ADCs. Here, we also present the first-in-neuroblastoma study with the AXL-targeted ADCT-601, which we will further develop as the MES-targeted arm of a combination treatment strategy with ADRN-targeted agents, such as standard chemotherapy and/or ALK inhibitors.