Human adenovirus F41 (HAdV-41), norovirus genogroup II (HNV-GII), rotavirus group A (RVA), and hepatitis A virus (HAV) are responsible for millions of illnesses every year in Canada. Wastewater-based epidemiology is one way to monitor the prevalence of these underreported (HAV) and non-reportable (HAdV-41, HNV-GII, RVA) food and waterborne enteric viruses. In this study, we monitored the presence of these four viruses in wastewater over 16 months from September 2022 until December 2023 using samples from two locations in southern Ontario. Viruses in 286 wastewater samples were concentrated using PEG precipitation and quantified using a multiplex RT-qPCR assay for HAdV-41, HNV-GII, and RVA, and a singleplex RT-qPCR assay for HAV. In agreement with historical clinical data, HNV-GII and RVA had seasonal peaks in wastewater in the winter (HNV-GII, up to 1.09 × 10