Spot blotch, caused by the fungal pathogen Bipolaris sorokiniana, is a destructive foliar disease of wheat in areas with hot and humid conditions, especially South Asia and South America. Chinese wheat genotypes have often been used as resistance donors to this disease, and resistance genes Sb2, Sb3, and Sb4 were all identified in Chinese materials. In this study, a panel of 258 bread wheat genotypes, compiled initially for Fusarium head blight screening, was evaluated in this study for field spot blotch resistance. This panel comprised 138 Chinese and 120 non-Chinese genotypes of worldwide origin. Field experiments were conducted in the Agua Fria experimental station, Mexico, during the 2020-2021 and 2021-2022 cropping seasons, using artificial inoculation complementing natural infection. Disease scoring was conducted four times using the 00-99 double digit scale at weekly interval during each season. Distribution of spot blotch severity (AUDPC) skewed towards the low disease direction in both seasons, and AUDPC exhibited a significant negative correlation with days to heading (DH). Raw AUDPC values were adjusted for DH and there were 117 genotypes exhibiting better resistance compared to the resistant check ‘Chirya’, 86 of which are Chinese genotypes. Genotyping was performed with the DArTseq® technology, and a genome-wide association study (GWAS) was conducted on the panel to detect significant marker-trait associations (MTA). The MLM algorithm in TASSEL detected seven MTAs at p < 0.001 on chromosomes 1A, 2A, 4A (2 MTAs), 5A (2 MTAs) and 5B, which were significant in both years, along with more MTAs significant in single years. The seven MTAs explained phenotypic variation between 4.9-13.2% and showed an additive mode of action. This study demonstrated a quantitative inheritance of field spot blotch resistance in the panel, and an additional field trial will be conducted during the 2022-2023 cycle to confirm the stability of the resistant genotypes as well as the MTAs.