This study investigated the influence of peer influence on school library use among public secondary schools in Lagos State, Nigeria. The study adopted survey research design. The study population comprised 16,366 students in public secondary schools in Lagos State. Structured questionnaire was used for the data collection and the Cronbach alpha value ranged from 0.7 to 0.9 which shows that the instrument is valid. Findings showed that students in public secondary schools in Lagos State, Nigeria used school library twice a week (mean = 3.00, SD = 0.79). School library was used daily among students in public secondary schools in Lagos State, in order to enable them to study and perform well in their studies (x̅ = 3.33). The extent of peer influence on library use was moderately high (the mean = 2.91, SD = 0.86). Peer pressure exerted high influence at (x̅ = 3.05) and peer academic value at mean = 2.76. Peer influence has a negative significant influence on school library use among students in public secondary schools in Lagos State, Nigeria (R2 = 0.025, β = -0.157, t = -5.781, p<0.05). Therefore, this study recommends that school administrators and librarian should care for each student in situation where there is negative influence it should be observed and corrected before it becomes a public menace.