To engage students in applying scientific process skills to real-world issues, we implemented a service-learning project model in our undergraduate introductory biology course for science majors. This model illustrates how we integrate inquiry inside and outside of the classroom through four steps: service, learning, classroom, and community. Out-of-class activities engaged students in serving the community (Service step) while deepening their learning experience beyond what they would learn in a classroom (Learning step). To connect the service-learning project with scientific process skills, students were asked to identify problems that our community partners were trying to solve, identify proposed solutions, and design ways to evaluate those solutions (Classroom step). Additionally, students connected their service-learning topic with core concepts in Biology. After their service, students used metrics to analyze their impact. Students then synthesized the connection between their service, learning, and classroom projects by presenting their findings to the scientific and lay communities through a poster session (Community step). Here we provide details of the model, recommendations, and examples for others to execute an inquiry-based service-learning project.