Abstract <p>Tomato (<i>Solanum lycopersicum</i> L.) is a globally important crop, frequently threatened by <i>Alternaria alternata</i>, the causative agent of leaf blight, which results in significant yield losses. Conventional chemical fungicides though effective but pose environmental and health risks and can also lead to development of resistant pathogens. The study explores the potential of endophytic fungi isolated from wild tomato (<i>Solanum pimpinellifolium</i> L.) as biological control agents against <i>A. alternata</i>. Endophytic fungi were obtained from healthy leaf tissues of wild tomato and characterized morphologically and molecularly. Altogether, 205 endophytic isolates were isolated and the endophytes comprised of fungal genera <i>Colletotrichum, Alternaria, Phomopsis, Phyllosticta, Curvularia, Aspergillus</i> and <i>Penicillium</i>. Maximum endophytes were obtained in Potato dextrose agar medium and least was isolated in Water agar medium amended with host plant extract. Samples collected from different sites showed rich diversity of endophytic fungi. Out of the total isolates, 53.57% showed antifungal activity against <i>A. alternata</i>. The endophytic fungi that showed prominent growth inhibition property against <i>A. alternata</i> were <i>Colletotrichum kahawae</i> SPB13<i>, Colletotrichum gloeosporioides</i> SPB103<i>, Phyllosticta fallopiae</i> SPK5, and <i>Penicillium sumatraense</i> SPK28. The results indicated that endophytic fungi from wild tomato have potential as eco-friendly biocontrol agents, offering sustainable alternative to synthetic fungicides in the management of tomato leaf blight caused by <i>A. alternata</i>.</p>