This study examined the extent of trust deficit in political governance among tertiary institution undergraduate students of Nigeria in political governance. The study adopted the descriptive survey research design. Multi-stage sampling procedure was adopted to sample 780 undergraduate students of Colleges of Education, Polytechnics and Universities in Osun State, Nigeria. An 18-item research instrument titled “Empirical Trust Deficit Survey in Political Governance” was used in data collection. The items were polytomously scored using a five-point Likert scale ranging from Strongly Disagree (SD, rated 1), Disagree (D, rated 2), Neither Agree nor Disagree (NAD, scored 3), Agree (A, given point 4); and Strongly Agree (SA, given point 5). The instrument was validated by three experts in Psychology and Educational Tests and measurement; administered on 90 tertiary undergraduate students in Osun State, Nigeria outside the study area; and yielded internal reliability index of 0.78. Data collected was analysed using descriptive statistics of simple percentage. Results showed that tertiary institution undergraduate students of Nigeria had distrust in political governance as the level of performance of their political office holders is low. Furthermore, undergraduate students of Nigeria neither agreed nor disagreed that economic inequality contributes to their distrust in political governance. Finally, there was a huge gap between campaign promises made by Nigerian politicians and fulfilment leading tertiary institution undergraduate students to develop loss of trust in them. It was recommended among others that there should be adequate monitoring in political governance in Nigeria to ensure that at least over 60% of the campaign promises made during election are fulfilled.