Several tomato production regions in Korea were surveyed for tomato yellow leaf curl disease (TYLCD). Tomato leaf samples showing TYLCD-like symptoms were collected from Tongyeong (To), Geoje (Gi), and Gimhae (Gh) cities of the southern part of Korea. Tomato yellow leaf curl virus (TYLCV) was detected and the full-length genomes of the isolates were sequenced. The TYLCV isolates found in Korea shared high sequence identity (> 99%) with TYLCV-IL [JR:Omu:Ng] (AB110217). Phylogenetic relationship analysis revealed that they formed two groups (with little genetic variability), and the To, Gj, and Gh isolates belonged to the TYLCV-IL group. An infectious clone of TYLCV-To (JQ013089) was constructed and agroinoculated into Nicotiana benthamiana, Nicotiana tabacum var. Xanthi, Petunia hybrida, Capsicum annuum, and Lycopersicon esculentum cv. Hausumomotaro. Agroinfection with a dimeric infectious clone of TYLCV-To induced severe leaf curling and stunting symptoms in these plants, excluding C. annuum. Tomato plants then developed typical yellow leaf curl symptoms.