The sustainable development of the environment and society depends not only on firms’ social responsibility initiatives, but also on employees’ socially responsible behavior during their daily work life. Hence, it is important to study why and how employees go about the socially responsible behaviors (SRB), such as environmental protection and charitable donations. Although research has been done on the antecedents of employees’ SRB from personal, contextual and leadership perspectives, little is known about the mechanism through which they affect these behaviors. Moreover, compared with the other two perspectives, research from the leadership perspective is relatively scarce. In this paper, we aim to fill these research gaps. Based on 936 respondents from 109 corporations, we empirically test the cross-level direct effect of ethical leadership on employees’ SRB and the cross-level mediating effect of perceived organizational virtuousness. In our empirical analyses, we adopt statistical methodologies such as hierarchical linear modeling and multilevel mediation analysis. Our results show that perceived organizational virtuousness partly mediates the influence of ethical leadership on employees’ environmental protection and charitable donation. In other words, ethical leadership enables employees to form the perception of organizational virtuousness, and therefore employees are more engaged in environmental protection and charitable donations. This research provides important insights for firms and their employees to become more socially and environmentally responsible.