Phosphorus (P) availability is a key determinant of many terrestrial ecosystem processes. In the boreal forest, P is tightly cycled, and can be heterogenous in its distribution across the landscape. Characterizing chemical, physical and landscape-scale drivers of variability in both concentration and forms of soil P can help us understand how P uptake, cycling and export will respond to disturbances and global environmental change, however, data on forms of soil P in boreal forests are sparse. The goal of this study was to assess the variability of soil P form and concentrations across a boreal forested watershed. We took surface 74 soil samples ( depth = 0 to 30 cm) to characterize soil P fractions in 2019. Soil samples were analyzed for a suite of chemical and physical characteristics, and were paired with geospatial data to develop predictive models of forms of soil P. Water extractable P concentrations were low (<2.2 mg kg-1) and only detectable in five of the samples. Total P (40 to 2147 mg kg-1) and plant-available (Mehlich-3 extractable) P (0.5 to 193 mg kg-1) concentrations varied widely across the study area. Multivariate regression models suggest that pH and metal concentrations (manganese, magnesium)are predictive of plant-available P (r2 = 0.57; RMSE = 0.87), while organic carbon and topography are predictive of total P (r2 = 0.45; RMSE = 0.17). These results suggest that soil P can vary widely, even in nutrient poor boreal ecosystems, and site-specific characteristics may play an important role in predicting variability.