Tomato, the most widely cultivated vegetables globally, is significantly threatened by biotic factors, particularly root-knot nematodes (RKNs) like Meloidogyne species, which are polyphagous parasites with a broad host range. Weeds play a crucial role as alternative hosts for RKNs, enabling their persistence in fields and serving as reservoirs of infection for subsequent crops. This study focuses on the Kolar district of Karnataka, India, a major tomato-producing region, where prominent weed hosts of RKNs are identified which include Mesosphaerum suaveolens, Crassocephalum crepidioides, Spermacoce ocymoides, Portulaca oleracea, Solanum nigrum, Alternanthera sessilis, Ageratum conyzoides and Emilia sonchifolia showing symptoms of nematode infection, such as gall formation. Morphological identification of nematode species revealed the presence of Meloidogyne incognita, M. javanica, and M. enterolobii. The findings underscore the importance of managing weed populations to control nematode infestations and mitigate their impact on tomato cultivation.