Addressing complex global sustainability challenges requires a creative mindset, yet current engineering curriculum does not facilitate development of student creativity. Design thinking, as defined by the Hasso Plattner Institute of Design at Stanford, is a human-centered, creative design methodology that can be used to foster cognitive aspects of student creativity. This empirical study evaluates the impacts of a design thinking process on student performance, including product creativity as a group measure and students’ individual perspectives of creativity within the context of sustainable engineering. Data was collected in three semesters of an undergraduate sustainable engineering course, two of which implemented design thinking. Student performance on sustainability design challenges was evaluated across four dimensions: novelty, usefulness, sustainability, and application of a design thinking process. Self-reported assessment methods, including pre- and post-surveys and focus groups were used to assess students’ perceptions of their creativity. Groups of students exposed to design thinking had significantly higher design project scores across the novelty, sustainability, and design thinking dimensions. This suggests that design thinking may enhance the quality of solutions to sustainability challenges in terms of creativity and sustainable design. Individually, students became more confident about their ability to be creative as a result of this course and the unique characteristics of design thinking. Collectively, our results suggest that incorporating design thinking into the engineering classroom facilitates student development of a creative cognitive process, enabling innovative solutions to complex engineering and sustainability challenges.