Cybersecurity is one of the main challenges faced by companies in the context of the Industrial Internet of Things (IIoT), in which a number of smart devices associated with machines, computers and people are networked and communicate with each other. In this connected industrial scenario, personnel need to be aware of cybersecurity issues in order to prevent or minimise the occurrence of cybersecurity incidents and corporate data breaches, and thus to make companies resilient to cyber-attacks. In addition, the recent increase in smart working due to the COVID-19 pandemic means that the need for cybersecurity awareness is more relevant than ever. In this study, we carry out a systematic literature review in order to analyse how the existing state of the art deals with cybersecurity awareness in the context of IIoT, and to provide a comprehensive overview of this topic. Four areas of analysis are considered: (i) definitions of the concepts of cybersecurity awareness and information security awareness, with keyword extrapolation (e.g. cybersecurity control level, information and responsibility); (ii) the industrial context of the analysed studies (e.g. manufacturing, critical infrastructure); (iii) the techniques adopted to raise company awareness of cybersecurity (e.g. serious games, online questionnaires); and (iv) the main benefits of a large-scale campaign of cybersecurity awareness (e.g. the effectiveness of employees in terms of managing cybersecurity issues, identification of cyber-attacks). Practitioners and researchers can benefit from our analysis of the features of each area in their future research and applications. •A literature review on cybersecurity awareness in IIoT contexts is conducted.•There are different definitions of cybersecurity awareness but with common keywords.•Some industries more than others are addressing cybersecurity awareness issues.•Several techniques support companies in complying with cybersecurity policies.•Improving cybersecurity awareness provides benefits to companies.