Successful social interactions require using knowledge about other individuals, groups, and their relationships. Previous neuroimaging studies identified regions of the human cerebral cortex that may represent each of these types of social information. However, because it is difficult to compare statistically significant results across studies, it is unclear whether each region represents only one type of social information, or whether each region represents multiple types of information. Here, we simultaneously map the cortical representation of individual traits, interpersonal relationships, social groups, social networks, and subjective judgements in individual subjects. To do this, we used a voxelwise encoding model approach with functional MRI (fMRI) data collected while six subjects answered questions about a fictional social network. In all subjects, voxels in the left temporal parietal junction (TPJ), left precuneus, and left superior frontal gyrus (SFG) represent individual traits. A separate set of voxels in bilateral TPJ, bilateral precuneus, bilateral SFG, and bilateral inferior frontal gyrus represent both individual traits and interpersonal relationships. Finally, voxels in the left medial prefrontal cortex represent subjective judgements. In contrast, the representations of social networks and social groups appear to be highly variable, noisy, and inconsistent across subjects.