Agricultural economists are increasingly incorporating insights from psychology into their research to better understand farmers’ behavior. The Big Five model of personality is frequently used in psychological research. This paper aims at answering how and when researchers use the Big Five personality traits when focusing on farmers (research questions, measurement of personality traits). In addition, we analyze to what extent the Big Five personality traits contribute to explaining farmers’ behaviors and outcomes. To answer these research questions, we carry out systematic literature research guided by the PRISMA approach. We searched three databases (Web of Science, Scopus, PubMed) at the end of February 2022 and identified n = 36 eligible studies. We included studies, which were written in English, which focused on farmers, including primary data and measurements of the Big Five personality traits. This is the first systematic and comprehensive review of the role of the Big Five personality traits in farmers’ behavior. Our review shows an increase in interest in the farmers’ Big Five personality traits in the past years, most often incorporated in research conducted in Europe. By carrying out the main steps of content analysis, we develop a taxonomy, categorizing the research aims of the reviewed studies. We identify three main categories: well-being (human and animal), business (in a broad sense and in a narrow sense), and methodological aims. Overall, our review suggests that some personality traits are more important for understanding farmers’ behaviors and outcomes than others, depending on the context. Indeed, we were able to identify some patterns. For instance, our review shows that neuroticism is most often negatively related to measures of human well-being, or business development, whereas agreeableness supports non-technical skills and education. Openness and extraversion seem to be strong predictors of pro-environmental behavior, whereas conscientiousness tends to increase business performance. To assess the possible risk of bias in the reviewed studies, we included a quality discussion. We further discuss the limitations of our review and identify avenues for future research. To increase the review’s credibility, we pre-registered our procedure (INPLASY202230138, DOI: 10.37766/inplasy2022.3.0138).