Obesity is a major global health concern linked to chronic inflammation, insulin resistance, and increased risk of metabolic diseases such as type 2 diabetes and cardiovascular disorders. Adipokines, a group of signaling proteins secreted by adipose tissue, play critical roles in regulating metabolic and inflammatory pathways. Accurate monitoring of adipokine levels can provide valuable insight into the onset and progression of obesity-related complications. However, traditional detection methods such as ELISA face limitations in sensitivity, throughput, and real-time analysis. Surface plasmon resonance (SPR) and localized surface plasmon resonance (LSPR) biosensors offer powerful label-free alternatives that enable dynamic and multiplexed detection of biomolecular interactions. This review presents the fundamental principles of SPR and LSPR, outlines key sensor components, and highlights the advantages of label-free detection. It also examines major adipokines relevant to obesity, current analytical challenges, and the urgent need for multiplexed biosensing in clinical applications. Engineering strategies for enhancing sensitivity, including nanostructured materials, surface functionalization, and signal amplification, are discussed alongside recent implementations of multiplexed SPR and LSPR platforms. Clinical studies demonstrating their utility in distinguishing obese from lean individuals and tracking metabolic status are reviewed. Finally, the paper addresses technical barriers, such as standardization and reproducibility, and explores future directions including portable devices, non-invasive sampling, and AI-driven data analysis. SPR and LSPR biosensors hold significant promise for advancing personalized diagnostics and improving the clinical management of obesity.