Women have been underrepresented in STEM fields around the world (UNESCO, 2018). Prior research identified some of the reasons for this gender disparity such as systemic barriers, lack of confidence, lack of female role models, and cultural and gendered science stereotypes. These issues have been framed in contemporary literature within the construct of STEM identity. Building upon this literature, our project explored the role of the university classroom in supporting the development of a strong STEM identity and specifically the view of self as a competent science person. The project consisted of two parts. In the first part student-led desktop and empirical research focused on generating evidence-based recommendations for how an introductory Calculus course could be redesigned to be more gender-inclusive. The second pertained to the evaluation of the redesigned Calculus course centered around two main indicators of success: (i) students’ confidence as mathematics learners, and (ii) their intention to continue with STEM education. The project has scientific and practical implications as it contributes evidence towards understanding the kinds of activities that might support university students’ STEM identity development and provides a set of concrete, evidence-based, gender-inclusive instructional practices.