The heterogeneity and suboptimal efficacy of biological treatments and small molecule drugs necessitate their precise selection based on biomarkers that predict therapeutic responses in inflammatory bowel disease. Recent studies have identified numerous novel biomarkers predictive of responses to biologics and small molecule modulators, utilizing a variety of omics approaches in inflammatory bowel disease. In this review, we systematically examine baseline omics biomarkers that predict responses to biological therapies and small molecule drugs, drawing on literature from PubMed. Our analysis spans multiple omics disciplines, including genomics, transcriptomics (both bulk RNA and single-cell RNA sequencing), proteomics, microbiomics, and metabolomics, with particular emphasis on the impact of models integrating multiple omics datasets. Additionally, to further the field of precision medicine, we evaluated specific biomarkers that may exhibit distinct effects on responses to multiple therapeutic interventions.