The use of automated writing evaluation (AWE) in second language (L2) writing contexts has increased dramatically, as evidenced by the large body of research published on the topic over the past decade. Considering this, several systematic reviews on AWE have been published. Nevertheless, none of these review studies has exclusively focused on the use of Grammarly in L2 writing contexts. Therefore, this systematic review aimed to investigate the trends, methodologies, and results in Grammarly research involving L2 learners. Web of Science and Scopus were searched by title, abstract, and keywords for relevant peer-reviewed literature published between 2009 and 2023. Twenty-four studies met the inclusion criteria and were included in the analysis. Regarding trends and methodologies, results showed that the bulk of L2 research on Grammarly has incorporated a quantitative element. Studies also tended to involve university students and lasted shorter than 15 weeks. Thematic analysis revealed two affordances and a constraint regarding Grammarly in L2 writing. Namely, the AWE system has an effective instructional design that supports L2 English writing. However, it also lacks teaching presence due to feedback-related issues. The article concludes with pedagogical implications and directions for future research.