Electronic journals in libraries are essential for updating facilities and expanding services so that users can acquire the information they require. The modern epoch is marked by an information and knowledge revolution. Electronic materials are now available to libraries in a variety of formats. As a result of technology advancements and higher expectations in teaching and learning, 21st-century classrooms demand a lot from both teachers and students. Most parents nowadays purchase (smartphones, tablets, or laptops) for their children without realizing the educational benefits of these devices in allowing access to online learning materials. Electronic journals from libraries have proven to be quite useful to the growing number of students who have access to the internet. This is possible because to 21st-century technology, but it\u27s concerning because there isn\u27t much research on the subject in Nigeria. As a result, the impact of library electronic journals on students\u27 academic achievement in physics was investigated in this study. This study used a quantitative research approach using a simple repeated measures strategy. The Physics Achievement Test (= 0.891) was used to collect the data, which had been rigorously validated and trial-tested. A mixed-design repeated measures analysis of variance was used to analyze the data. Students\u27 physics grades were shown to be significantly improved when they read electronic publications from the library. As a result, in order to improve their academic performance, students should be exposed to the usage of library electronic journals