Drylands are arid and semi-arid areas whose main feature is their low level of precipitation. They cover nearly half of Earth’s land surface and are distributed worldwide, constituting the planet’s largest biome. Dryland soils have low fertility, are greatly affected by climate variability, and are vulnerable to wind and water erosion. The phosphorus-rich soil dust traveling by aeolian processes from drylands is the main source of P for the global primary productivity in P-limited areas, a fact that highlights the importance of arid and semiarid areas in the global nutrient budget. This review discusses the development of dryland soils, the sources of P in drylands, the C, N, P, relation in dryland soils, the fractionation and bioavailability of P, and biotic and abiotic factors affecting the P in drylands. Finally, the dynamic of P in biological soil crusts and resource islands is discussed. Combined, they contribute to the surface organic matter pools, alter the soil fertility, and are determinant factors in P’s availability in dryland soils. We conclude the review by highlighting the gaps in knowledge that should be addressed in future research regarding biological and abiotic processes that determine the dynamics of P in drylands.