In this paper, a novel series of nanohybrid of poly(octadecylacrylate derivatives) montmorillonite (ODA/MMT) was prepared by successfully dispersing the inorganic nanolayers of MMT-clay on the organic polymer matrix via in situ free-radical polymerization by different ratios. The prepared nanohybrid polymers were characterized by FTIR and Raman spectroscopy, X-ray diffraction (XRD), HRTEM, GPC, DSC, and TGA instruments. The XRD confirmed the presence of an exfoliated/interacted clay structure in the prepared polymer. Moreover, the molecular weight of the prepared polymer nanohybrids is higher than the corresponding polymer. The results of applying the polymer as pour point depressants showed a considerable reduction from 27 C (initial pour point) to −3 C, facilitating the process of oil flow at lower temperatures than earlier. The apparent viscosity of waxy crude oil was also decreased significantly by the addition of the (ODA/MMT) polymers, and the long-term stability of the prepared nanohybrid polymers was superior to that of a conventional polymer. The efficiency of polymers nanohybrid in reducing the pour point of crude oil associated with improved oil flow is one of the most important processes of charge and transportation process. The mechanism of enhancement of the flow properties by the polymers nanohybrid is predicted.