The impact of digital transformation on various aspects of daily life has necessitated the demand for digitally competent teachers who can facilitate students’ digital competence in a world increasingly mediated by digital technologies. This study is based on the European Framework for the Digital Competence of Educators (DigCompEdu), which is considered a comprehensive framework for describing the multifaceted nature of teachers’ digital competence. The study aims to assess the reliability and validity of the Greek version of the DigCompEdu Check-In as a self-reflection instrument and to determine the participants’ level of digital competence, both overall and by competence areas, in accordance with the DigCompEdu framework. This empirical research followed a quantitative, non-experimental, descriptive, correlational design and involved 208 in-service primary and secondary teachers in Greece. Exploratory and Confirmatory Factor Analysis (EFA and CFA) were performed using structural equation modeling (SEM) to determine the factorial structure of the instrument. The analysis confirmed the reliability and validity of the scale, as well as its underlying factorial structure. The findings indicated that the overall proficiency level of the participating teachers is moderate and identified “Teaching and Learning,” “Assessment,” and “Facilitating learners’ digital competence” as the least developed areas. These results underscore the need for teachers to increase their digital competence in the aforementioned areas through specific training to effectively integrate digital technology into their teaching practice.