<p>A variety of neurodevelopmental disorders collectively referred to as autism spectrum disorders (ASD) are characterized by limited, repetitive behaviors and deficiencies in social communication. Pharmacological therapies are frequently used to treat related symptoms like aggression, anxiety, and irritability; however, each person responds differently to treatment, frequently as a result of underlying genetic variances. To better understand the mechanisms of medication and balance symptom improvement against side effects, pharmacogenomic research has delved into genetic relationships with treatment response and adverse effects. As the most commonly used drug classes for ASD, antipsychotics, antidepressants, and stimulants have been the subject of the majority of pharmacogenomic research to date. The present understanding of pharmacogenomic intervention in ASD, its related clinical results, and new techniques such as genome-wide association studies (GWAS) and multi-omic approaches are highlighted in this review. Research gaps and a lack of established recommendations continue to restrict clinical deployment despite increased interest. Pharmacogenomics may improve treatment accuracy and decrease adverse medication reactions when incorporated into ASD therapy. A comprehensive literature search was performed using the PubMed, Scopus, and Web of Science databases to identify relevant published studies. The search strategy incorporated combinations of the keywords “pharmacogenomics,” “autism spectrum disorder,” “precision medicine,” “gene–drug interaction,” and “personalized therapy.” The inclusion criteria were limited to peer-reviewed, English-language studies involving human participants. Review articles, conference abstracts, animal studies, and publications without clear pharmacogenomic relevance were excluded. Preference was given to studies that offered mechanistic insights, clinical correlations, or genomic evidence supporting pharmacogenomic-guided therapeutic approaches in ASD.</p>