Background: There is clear consensus among influential education reports that an expansive range of intrapersonal (e.g., self-regulation) and interpersonal competencies (e.g., empathy) highly influence educational and career success. Research on teaching and learning these competencies is limited in engineering education. Purpose/Hypothesis: This study explores the impacts of a mindfulness training program on first-year engineering students and aims to understand potential impacts on the development of intrapersonal and interpersonal competencies. Design/Method: A four-session mindfulness-based program was designed, developed, and facilitated to cultivate intrapersonal and interpersonal competencies. Qualitative data were collected from a total of 35 students through a post-survey (n = 32), 3-month follow-up survey (n = 24), and interviews (n = 18). A thematic analysis process accompanied by validity and trustworthiness checks was employed to analyze the data. Results: The results suggest that the majority of students became more mindful, which led to improved intrapersonal competencies (e.g., self-regulation, focus, resilience, and well-being) and interpersonal competencies (e.g., empathy, communication, teamwork, and leadership). Discussion/Conclusions: The study provides compelling evidence that mindfulness training can support the development of intrapersonal and interpersonal competencies among engineering students, which can support their overall academic experience, personal, and professional development. Future design and development work will be needed to evaluate the integration and scalability potential of mindfulness training within engineering programs.