Plesiolebias is a genus of fish in the family Rivulidae. These annual killifish are endemic to seasonal pools, swamps and lagoons in the Araguaia–Tocantins, Xingu, and uppermost Paraguay (Pantanal) river basins in Brazil.

They are small fish, up to 5 cm (2.0 in) in total length. As typical of killifish, males are more colorful than females.

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