This article reports on the results of a multi-year, multi-phase international quantitative research investigation into perceptions of board chair leadership impact in nonprofit and voluntary organizations in Canada, the United States, and the United Kingdom. Specifically, this research tests four hypotheses and a hypothesized model derived from theoretical perspectives on chair leadership effectiveness that emerged when the results of a prior grounded theory research investigation were reviewed ex post facto through the lens of leadership literature (see Harrison and Murray, NPML, accepted). The purpose of this phase of the research is to determine: (a) whether there is empirical support for the theoretical perspectives advanced; and (b) which perspective offers the best explanation for why some board chairs are perceived as having more impact in the role than others. The results suggest chair leadership effectiveness is best understood as a multi-dimensional theoretical construct explained by more than one leadership theory. The article concludes with a discussion of the findings and directions for further research.