Murdannia is a genus of annual or perennial monocotyledonous flowering plants in the family Commelinaceae.

The genus is one of the largest in the family. They are most easily distinguished from other genera in the family by their three-lobed or spear-shaped antherodes (i.e. non-functional anthers). Also it is the only genus with staminodes (i.e. non-functional stamens) opposite the petals.

Murdannia are found in tropical regions across the globe with extensions into warm temperate areas. Typically, Murdannia species are found in open areas in mesic soils. However, some are semi-aquatic, and a limited few are found in closed forest situations. Three species are naturalized in the United States (Murdannia keisak, M. nudiflora and M. spirata).

The genus is named in honor of Murdan Ali, a plant collector who worked for John Forbes Royle and maintained the herbarium at Saharanpur, India. He was a munshi who took a keen interest in natural history and under the training of Falconer, Royle and Edgeworth had become a proficient botanist who compiled a vernacular flora of northern India and the Himalayas which was however never published.