The persistent disparities in educational resources and learning outcomes between students of different socioeconomic backgrounds and geographical locations remain a major challenge to equitable education in Nigeria. This study examined the role of artificial intelligence (AI) tutors in enhancing academic performance and bridging learning gaps among students in under-resourced public schools in Nigeria. A quasi-experimental research design involving 800 students drawn from ten Federal Government Colleges (FGCs), comprising five rural and five urban schools, was adopted. Participants were equally distributed between an AI tutor treatment group (n = 400) and a control group (n = 400). Academic performance was assessed using pre-test and post-test scores in Mathematics and English, while AI tutor exposure, school resources, teacher support, socioeconomic status (SES), and learning self-efficacy were also measured. The measurement scales demonstrated strong internal consistency, with Cronbach's alpha coefficients exceeding .84. Results revealed that students exposed to AI tutors significantly outperformed students in the control group, recording a 12.3-point advantage in post-test total scores (p < .001, Cohen's d = 0.81), indicating a large treatment effect. Furthermore, AI tutor use significantly moderated socioeconomic disparities in achievement (β = .18, p < .001), with low-SES students gaining 15.1 points compared with 9.2 points among high-SES students. In rural schools, AI tutor intervention closed approximately 62% of the urban-rural learning gap. The regression model explained 54.7% of the variance in post-test academic performance. The study concludes that appropriately implemented AI tutoring systems can substantially improve learning outcomes while promoting educational equity, particularly among socioeconomically disadvantaged and rural students. Strategic investment in AI-enabled learning infrastructure, teacher capacity development, affordable connectivity, and equitable access to digital learning technologies is therefore recommended for Nigerian public schools.