Trust in companies and their executives seems to have declined in recent years (Edelman Trust Barometer, 2018; Reputation Institute, 2018; Tonkiss, 2009), with consequences for the credibility of the entire economic system. At the same time, there is some evidence, that social responsibility is considered important for the long-term success of companies by university students, who represent the future entrants to the job market (Elias, 2004). Those future entrants seem to be interested in companies' responsible behavior and sustainable governance. In line with demographic challenges and resulting staffing bottlenecks, companies are challenged to position themselves as attractive employers in the job-market. Against this background, the discussion about trust, Corporate Social Responsibility (CSR) and the employer brand has gained traction. The objective of this paper is to conceptualize the relation between trust, CSR and the employer brand and to derive instruments for building trust via CSR and employer branding. Trust is understood as the "psychological state comprising the intention to accept vulnerability based upon positive expectations of the intentions or behavior of another" (Rousseau, Sitkin, Burt & Camerer, 1998). The paper describes elements and determining factors for trust and discusses the influence of CSR activities and the employer brand on employer choice and trust. Finally, instruments rooted in CSR and employer branding that enhance trust in companies are identified.