Gender Equality, Diversity and Social Inclusion (GEDSI) are critical in achieving the Sustainable Development Goals number 4 (Quality Education), number 5 (Gender Equality) and number 10 (Reduced Inequalities) , impacting various aspects of society, organizations, and individual well-being. While GEDSI issues are still a pressing issue worldwide, this study aims to design an instrument for the GEDSI situationer tool for students, administrative staff and faculty members. This instrument underwent a thorough validation and development process utilizing a mixed-method design. First, the item is designed through Focus Group Interviews (FGIs) on GEDSI in a prominent state university in the Philippines. Through Exploratory Factor Analysis (EFA)- using survey responses from 374 students and PLS-SEM for 40 faculty and 51 administrative staff, the study found that the data met all four fit statistics cutoffs outlined in the literature Cronbach alpha 0.9 excellent in most of the factors except for factor 1 of the Student Tool, which has a score of 0.78 acceptable , item loadings, average variance extracted (AVE) and composite reliability results. The validated GEDSI Situationer Tool proved to be a reliable technique for assessing gender related issues in the institution. This would help make evidenced-based decisions and develop solutions to create a more inclusive and equitable environment.