This chapter reviews research on individual differences in spatial cognition from a somewhat historical perspective. It commences with a review of the factor analysis literature, which dominated early research in spatial abilities. Then, the chapter considers research on the analysis of spatial abilities from the perspective of cognitive psychology. Individual differences in large-scale or environmental spatial abilities such as wayfinding and navigation are examined. Finally, it considers some of the functions of spatial ability in occupational and academic performance. The research reviewed in this chapter provides strong evidence that spatial ability is differentiated from general intelligence. It shows that spatial ability is not a single, undifferentiated construct, but composed of several separate abilities, such as spatial visualization, flexibility of closure, spatial memory, and perceptual speed. Recent research has also begun to analyze complex tasks involved in these professions in terms of their demand on spatial skills.