Prior research has established many factors which are linked with mental illness stigma (MIS). One such factor is that of socioeconomic status (SES). The current research intended to address if the link between SES, specifically income level, and MIS might be explained by social dominance orientation (SDO) and the legitimizing myth that mental illness onset is controllable in nature. A sample of 926 participants reported their level of household income and completed self-report measures of MIS, SDO, and mental illness controllability attributions (MI-Control). Results demonstrated that higher levels of income were associated with higher levels of MIS, SDO, and MI-Control. Furthermore, a significant three-path mediated effect was found from SES to MIS through SDO and MI-Control. Findings highlight the extent to which sociodemographic factors may be linked with negative attitudes toward those with mental illnesses, particularly when such factors work in tandem with competitive social worldviews. Implications in regard to the importance of socioeconomically diverse mental health funding committees are discussed.