Chromatography, a fundamental polymer characterization technique, is covered extensively in this chapter. This subsection provides an in-depth exploration of chromatographic methods tailored specifically for polymer analysis. It discusses the principles behind chromatography, including the separation mechanism based on differences in molecular interactions with the stationary phase. Various chromatographic techniques are elucidated, along with their applications in characterizing polymers based on molecular weight distribution, chemical composition, and structural heterogeneity. Additionally, the subsection addresses recent advancements and emerging trends in chromatographic techniques for polymer characterization, highlighting their significance in advancing our understanding of polymer properties and behaviour.