Abstract: Noroviruses (NoV) are the most common cause of epidemic gastroenteritis, accounting for 95% of viral gastroenteritis outbreaks worldwide. NoV detection is difficult because they are genetically heterogeneous and cannot be grown in cell culture. The principle detection method utilized by diagnostic laboratories is quantitative RT-PCR (qRT-PCR). The accuracy of a qRT-PCR assay relies on the generation of a standard curve using a positive control with a known genome copy number. To that end, we have developed quantitative synthetic standards that include conserved sequences from NoV GI and NoV GII for the detection and quantification of NoV from either clinical, food, or environmental samples. These quantitative synthetic molecular standards provide well-characterized reference materials for the detection and quantification of NoV by qRT-PCR. Further, they exhibit excellent compatibility with numerous published NoV assays and can be used as controls for assay development, verification, and validation.