Soil fauna plays an essential role in agricultural productivity as it mediates nutrient cycling and soil organic matter dynamics, alters soil physicochemical properties and supports plant growth. Nitrogen fertilization may have a positive or negative influence on soil fauna in a manner that alters ecosystem functioning, but these links have not yet been quantified in a generalized manner. We present the results of a global meta-analysis of available literature data on the effects of nitrogen fertilization on taxonomic and ecological groups of soil fauna. Our results show that nitrogen fertilization increases the abundance of nematodes (+36%), springtails (+29%), mites (+35%), and the biomass of earthworms (+15%) compared to when no fertilizer is applied. The meta-analysis for different nematode feeding groups and life-form groups of springtails, mites and earthworms showed that organic fertilization has an overall positive effect on most taxonomic groups as opposed to inorganic fertilization, which has neutral or negative effects on most taxonomic groups. Additional meta-analyses showed that the effects of nitrogen fertilization on soil fauna depend on the intensity of the fertilization regime, on soil physicochemical properties as well as on climatic conditions. Our findings suggest that the adoption of less intense farming practices such as organic fertilization combined with site-specific nitrogen fertilization regimes is a suitable strategy for protecting and enhancing functional communities of soil fauna.