Tourism has emerged globally as a strategic sector for economic diversification, employment generation, and social stability, particularly in developing countries seeking alternatives to resource dependence. In Nigeria, prolonged reliance on crude oil revenues has produced structural vulnerabilities, including unemployment, regional inequality, and insecurity, intensifying the need for diversification strategies capable of also addressing conflict drivers. While a growing body of scholarship has examined tourism’s economic contribution in Nigeria, and a separate body has examined tourism-peace linkages elsewhere in Africa, few studies have theorised the two relationships jointly within a single Nigerian framework. This paper addresses that gap by using the Tourism-Led Growth Hypothesis and Peacebuilding Theory as a combined analytical lens to examine tourism’s dual contribution to diversification and peacebuilding in Nigeria. Using a qualitative desk-review methodology, the article draws on peer-reviewed literature, institutional statistics (UNWTO, WTTC, NBS, CBN, AfDB), and policy documents published largely between 2017 and 2026. Findings show that tourism contributed roughly 3.6-3.9% of Nigeria’s GDP and around 2.7 million jobs by 2024, figures that remain far below comparator economies such as Morocco (12.2%), Rwanda (9.8-10.3%), Botswana (approximately 10% including indirect effects) and Kenya (7-10%), pointing to substantial untapped capacity. The evidence also indicates that community-based tourism models, where local populations retain a stake in benefit distribution, correlate with stronger peacebuilding outcomes than externally driven, elite-captured tourism development. However, insecurity, weak infrastructure, fragmented governance, and limited financing continue to constrain the sector. The paper concludes that tourism can serve as a viable instrument for inclusive growth and sustainable peace in Nigeria, but only where investment in infrastructure and security is paired with deliberate, community-anchored governance reform.