Significance: Human activities have resulted in large increases in the availability of nutrients in terrestrial ecosystems worldwide. Although plant community responses to elevated nutrients have been well studied, soil microbial community responses remain poorly understood, despite their critical importance to ecosystem functioning. Using DNA-sequencing approaches, we assessed the response of soil microbial communities to experimentally added nitrogen and phosphorus at 25 grassland sites across the globe. Our results demonstrate that the composition of these communities shifts in consistent ways with elevated nutrient inputs and that there are corresponding shifts in the ecological attributes of the community members. This study represents an important step forward for understanding the connection between elevated nutrient inputs, shifts in soil microbial communities, and altered ecosystem functioning.