α-Synuclein is a small protein whose fibrilation is linked to a variety of neurodegenerative diseases, collectively called as synucleinopathy. Parkisnson’s disease (PD) is one of them and is well characterized. Plants accumulate metabolites which possess multiple therapeutic activities such as anti-cancer, anti-tumor, anti-inflammatory and anti-oxidant properties and are also associated with less side effects compared to synthetic compounds. In the current study, we have investigated the therapeutic potential of a chalcone based plant metabolite butein against α-Syn fibrillation and to understand the mechanism of a fibrillation inhibition under physiological conditions employing a combination of spectroscopic, calorimetric, microscopic and computational methods. The ThT and light scattering kinetics studies shows that butein inhibits α-Syn fibrillation. ITC and docking results show that butein binds with α-Syn in a sequential manner and establishes multipoint contacts. The energetics of interactions suggest that butein interferes in the hydrogen bonding and hydrophobic interactions, and thus inhibits α-Syn fibrillation. This was also supported by ANS binding studies. MD simulations indicate that binding of butein reduces the structural flexibility in α-Syn, resulting in a delay in onset of structural transitions into β-sheets rich structures. This is also indicated by CD results. Our results suggest that investigation of the effects of such molecules on α-Syn fibrillation is important in recognizing effective inhibitors and designing therapeutic strategies for synucleinopathies.