Poa annua, or annual meadow grass (known in America more commonly as annual bluegrass or simply poa), is a widespread low-growing turfgrass in temperate climates. Notwithstanding the reference to annual plant in its name, perennial biotypes do exist.

It originated as an allopolyploid hybrid between Poa supina and Poa infirma. Major chromosomal rearrangements after polyploidy have contributed to variation in genome size in Poa annua.