Slimy sculpin (Cottus cognatus) are found throughout much of North America; however, their presence has never been recorded on Prince Edward Island (PEI), Canada. After slimy sculpin were discovered in one river in western PEI (Big Pierre Jacques River), all of the rivers on PEI were sampled to determine their distribution. Sculpin were discovered in one additional watershed, the Brae River, which is separated from the Big Pierre Jacques by one watershed. In both rivers, all age classes of sculpin were present, indicating a healthy population. As there are no historical records of slimy sculpin in the province, it is not known whether these fish were introduced to the area, or whether they were historically present but were extirpated from other rivers across the province.