The growing interest in melanin‐like materials makes a strong request for fabrication strategies, modulation methods of their morphologies and properties, and profound knowledge of their structure–property relationship. In this review, we summarize the state‐of‐the‐art modulation methods of melanin‐like materials, with respect to both their chemical structures and morphologies. The change of chemical structures and morphologies of these materials manipulates their inherent properties, leading to broadening applications of melanin‐like materials. The methodology combining various characterization methods and theoretical calculations not only shows advantages for clearly identifying the molecular engineering of melanin‐like compounds but also sheds light on fully understanding their properties. This fundamental work provides researchers with great diversity and choices of fabrication and modulation methods based on the specific demands of emerging applications. © 2016 Society of Chemical Industry