Purpose: This study is a quantitative exploration of a new construct the authors label as "academic culture (AC)." Treating it as generalized latent variable composed of academic press (AP), disciplinary climate (DC), and teachers' use of instructional time, the purpose of this paper is to explore the potential of this construct to be a key mediator of school leaders' influence on student learning. The study is guided by three hypotheses. Design/methodology/approach: Responses by 856 elementary teachers from 70 schools to an online survey measured the three components of AC along with school leadership (SL). Provincial tests of writing, reading, and math were used as measures of student achievement (SA). Social economic status (SES) was used as control variable for the study. Data were summarized using descriptive statistics and correlations were calculated among all variables. Analyses included intra-class correlation analysis, regression equations, confirmatory factor analysis, and structural equation modeling. Findings: Evidence confirmed the study's three hypotheses: first, AP, DC, and instructional time formed a general latent construct, AC; second, AC explained a significant proportion of the variance in SA, controlling for student SES; and third, AC was a significant mediator of SL's influence on SA. Concepts and measures of academic optimism (AO) and AC are compared in the paper and implications for practice and future research are outlined. Originality/value: This first study of AC explored the relationship between AC and SA. Although at least two AO studies have included measures of distributed leadership, minimal attention has been devoted to actually testing the claim that AO is amenable to the influence of explicit leadership practices (as distinct from enabling school structures) and is a powerful mediator of SL effects on student learning. Addressing this limitation of AO research to date, the present study included a well-developed measure of leadership practices and assessed the value of AC as a mediator of such practices.