Background Research into public risk perceptions associated with emerging risks in agriculture and supply chains has focused on technological risks, zoonotic diseases, and food integrity, but infrequently on naturally occurring diseases in plants. Plant virus infections account for global economic losses estimated at $30 billion annually and are responsible for nearly 50% of plant diseases worldwide, threatening global food security. This research aimed to understand public perceptions of emerging risks and benefits associated with plant viruses in agriculture in Belgium, Slovenia, Spain, and the UK. Methods Online qualitative semi-structured interviews with 80 European consumers were conducted, including 20 participants in each of Belgium, Slovenia, the UK, and Spain. Microsoft Streams was used to transcribe the interview data, and NVivo was utilized to code the transcripts and analyze the data. Results The results indicate that, while study participants were relatively unfamiliar with the plant viruses and their potential impacts, plant viruses evoked perceived risks in a similar way to other emerging risks in the agri-food sector. These included risks to environment and human health, and the economic functioning of the relevant supply chain. Some participants perceived both risks and benefits to be associated with plant viruses. Benefits were perceived to be associated with improved plant resistance to viruses. Conclusions The results provide the basis for risk regulation, policy, and communication developments. Risk communication needs to take account of both risk and benefit perceptions, as well as the observation that plant viruses are perceived as an emerging, rather than an established, understood, and controlled risk. Some participants indicated the need for risk–benefit communication strategies to be developed, including information about the impacts of the risks, and associated mitigation strategies. Participants perceived that responsibility for control of plant viruses should be conferred on actors within the supply chain, in particular primary producers, although policy support (for example, financial incentivization) should be provided to improve their motivation to instigate risk mitigation activities.