This study examined the relationship between regional integration and state behaviour and international cooperation in Uganda, focusing on Uganda's engagement with the East African Community (EAC) framework. Guided by three objectives-assessing Uganda's regional integration engagement, establishing the nature of its international cooperation behaviour, and determining the relationship between the two-the study adopted a descriptive cross-sectional and correlational design. From a target population of 130 foreign affairs, trade, and security stakeholders, a sample of 97 respondents was selected using Krejcie and Morgan's (1970) table and stratified random sampling. Data were collected through a five-point Likert-scale questionnaire and analysed using SPSS, employing descriptive statistics, Pearson correlation, and simple linear regression. Results showed a high overall Regional Integration Index (M = 3.62) and a high overall State Behaviour/Cooperation Index (M = 3.52), with protocol ratification/domestication and compliance with regional commitments rated only moderately. A moderately strong, positive, and statistically significant correlation was found between regional integration and cooperative state behaviour (r = 0.579, p < 0.01), and regression analysis confirmed that regional integration significantly predicts state behaviour (β = 0.529, p < 0.01), explaining 33.5% of the variance (R² = 0.335). The study concludes that deeper regional integration engagement is associated with more cooperative Ugandan state behaviour internationally, though this relationship operates within a wider context of domestic political and governance factors, and recommends accelerated protocol ratification, stronger inter-agency coordination, and continued investment in EAC political and security cooperation.