Climate change is predicted to shift forest compositions; however, most models have focused on abiotic factors like climate and soil, and largely ignored biotic interactions. Understanding how competition might influence tree growth in these ecosystems is needed to improve these models. We established 16 plots across Algonquin Provincial Park, southeastern Ontario, and sampled 240 trees of 3 different species (Pinus strobus [eastern white pine], Pinus resinosa [red pine], and Quercus rubra [northern red oak]) to compare growth rates and competition between these three species based on a spectrum of stand positions, stand densities, and species compositions using standard dendrochronological sampling procedures. Across stand positions, red oaks had the smallest difference in growth on average between upper and lower canopies at 29.56% lower, whereas white pines had the largest difference in growth at 46.61% lower. This difference may be driven by the shade tolerance of white pines, which can persist in the understory with less annual growth, while the red oaks don’t survive. Increasing stem density was associated with significant decreases in annual growth in both the upper and lower canopies for all species, which follows established trends in the literature. Between species, oaks growing underneath a canopy of other oaks or pines had no significant difference in growth, which reflects the similarity in shade tolerance between red oaks and red pines. White pines, meanwhile, grew significantly more under a canopy of red oaks or red pines as opposed to under a canopy of other white pines. This research supports the need to consider species interactions and competition in modeling future range shifts.