Research has established that GPS use negatively affects environmental learning and navigation in laboratory studies. Furthermore, the ability to mentally rotate objects and imagine locations from other perspectives (both known as spatial transformations) is positively related to environmental learning. Using previously validated spatial transformation and environmental learning tasks, the current study assessed a theoretical model where long-term GPS use is associated with worse mental rotation and perspective-taking spatial transformation abilities, which then predicts decreased ability to learn novel environments. We expected this prediction to hold even after controlling for self-reported navigation ability, which is also associated with better spatial transformation and environmental learning capabilities. We found that mental rotation and perspective-taking ability fully account for the effect of GPS use on learning of a virtual environment. This relationship remained after controlling for existing navigation ability. Specifically, GPS use is negatively associated with perspective-taking indirectly through mental rotation; we propose that GPS use affects the transformation ability common to mental rotation and perspective-taking.