When and where renewable energy sources such as onshore wind turbines generate energy depends heavily on their spatial distribution. This distribution, however, derives from the preferences and restrictions imposed by local stake-holders and dictates the overall onshore wind land eligibility. Unfortunately, due to inconsistent analysis methods and a shifting sociotechnical landscape, current understanding of land eligibility is insufficient. Therefore the Geospatial Land Availability for Energy Systems (GLAES) model, a general framework for land eligibility investigation, is used to conduct a uniformly-constrained pan-European investigation of onshore wind land eligibility in which 31 socially and technologically driven constraints are imposed. A detailed characterization of the average wind resource and current land usage within the eligible areas is then discussed. Constraint sensitivity is then evaluated at both the European and national levels including the construction of a detailed sensitivity trend for all constraints. Ultimately, it is found that 26.24% of land is eligible across Europe, with the highest shares possessed by Spain, France and Sweden. On average across Europe, onshore wind land eligibility is most sensitive to the minimal wind speed, the maximal terrain slope, the maximal distance from power lines, and the minimal distance from settlements.