Background. Spatial ability (SA) has long been the focus of research in psychology, because it is associated with performance in science, technologies, engineering, and mathematics (STEM). Research has shown that males consistently outperform females in most aspects of SA, which may partially explain the observed overrepresentation of male students seeking STEM degrees. Objective. Tis study examines sex and feld of study (degree) diferences in diferent aspects of spatial ability and its structure. Design. We assessed SA by using an on-line gamifed battery, which included 10 spatial tests capturing 10 dimensions of spatial ability, among which were mental rotation, spatial visualization, spatial scanning, spatial reasoning, perspective-taking, and mechanical reasoning. Te sample consisted of 882 STEM (55% males) and Humanities (20% males) university students in Russia. Results. Males outperformed females on all assessed components of SA with a small efect size (1–11%). We also found that students from STEM felds outperformed Humanities students on all SA subtests (efect size ranged from 0.2 to 7%). Tese diferences by study choice were not fully explained by the observed over-representation of males in the STEM group. Te results of the study suggested no interaction between sex and degree. In other words, on average, males outperformed females, irrespective of whether they were STEM or humanities students; and the STEM advantage was observed for both males and females. Te same unifactorial structure of SA was observed in the STEM and Humanities groups. Conclusion. Our results are consistent with previous research, suggesting sex and study feld diferences in SA. Longitudinal research is needed to explore the causal mechanisms underscoring these diferences.