The feelings of reward associated with social interaction help to motivate social behaviour and influence preferences for different types of social contact. In two studies conducted in a general population sample, we investigated self-reported and experimentally-assessed social reward processing in personality spectra with prominent interpersonal features, namely schizotypy and psychopathy. Study 1 (n = 154) measured social reward processing using the Social Reward Questionnaire, and a modified version of a Monetary and Social Incentive Delay Task. Study 2 (n = 42; a subsample of Study 1) investigated social reward processing using a Social Reward Subtype Incentive Delay Task. Our results show that schizotypy (specifically Cognitive-Perceptual dimension) and psychopathy (specifically Lifestyle dimension) are associated with diverging responses to social scenarios involving large gatherings or meeting new people (Sociability), with reduced processing in schizotypy and heightened processing in psychopathy. No difference, however, occurred for other social scenarios—with similar patterns of increased antisocial (Negative Social Potency) and reduced prosocial (Admiration, Sociability) reward processing across schizotypy and psychopathy dimensions. Our findings contribute new knowledge on social reward processing within these personality spectra and, with the important exception of Sociability, highlight potentially converging patterns of social reward processing in association with schizotypy and psychopathy.