Tertiary education offers opportunities for intellectual, social, and personal growth, but it is also accompanied by numerous challenges, including academic pressures, social adjustments, and psychological stressors. In-session psychological well-being (SI-SPW) is critical during this phase, influencing academic performance and overall quality of life. Research indicates that a significant proportion of students experience psychological distress during active academic periods, often manifesting as stress, anxiety, or emotional exhaustion. Off-campus students may face additional challenges, such as social isolation, high educational expenses, and the need to balance work and study commitments, which can exacerbate these effects. This study investigates the roles of personality traits and sense of community in determining SI-SPW among off-campus students of a tertiary institution in Lagos State, Nigeria. Drawing on prior findings that link social connectedness and personal dispositions to mental health outcomes, the research explores how students’ interpersonal relationships, community engagement, and individual characteristics contribute to their emotional and psychological resilience during the academic session. Understanding these factors is essential for developing targeted interventions that support holistic student well-being, improve academic outcomes, and enhance overall life satisfaction. Findings from this study are expected to inform institutional policies and programs aimed at fostering supportive environments for off-campus students and promoting sustainable psychological well-being in higher education contexts.