Scapolite occurrences are widely observed in the metasedimentary rocks exposed around the Khetri Copper Belt and adjoining Nim ka Thana copper mineralized area in western India. Amoeboidal to well-developed and rounded/elliptical-shaped marialitic scapolite (Na-rich end-member) rich zones with variable Cl contents ranging from 1.0 wt % to 2.9 wt % have been identified in proximity to the ore-bearing hydrothermal fluid activity zones. Although scapolite is formed as a product of regional metamorphism in many places, in this study, we propose a strong possibility that scapolite was formed by hydrothermal ore-bearing fluid interaction with metasediments. The evidence of hydrothermal activity and Cl sourcing is attributed to (i) the absence of evaporite beds in the area and no Na-rich plagioclase as inclusions within the scapolite suggesting the formation of marialitic scapolite from sodic plagioclase in the metasediments with the interacting hydrothermal fluid; (ii) an epithermal to mesothermal hydrothermal fluid with moderate salinity responsible for the Cu mineralization that is ascribed to be the source of Cl for the formation of marialitic scapolite; (iii) diffusion of SO2 in the scapolite in close association with the sulfide mineral phase (chalcopyrite) supporting the involvement of ore-bearing fluid in the development of scapolite; (iv) the absence of zoned scapolite, the spatial distribution of scapolite in a particular lithology, the occasional incorporation of sulfur into marialitic scapolite and the texture/geometry in the scapolite suggesting a broad hydrothermal linkage instead of a pure metamorphic origin.