Mysella is a genus of marine bivalve molluscs of the family Lasaeidae.
Shells of Mysella are thin and concentrically striated. Shells range from small to moderately sized, are inequilateral, and has a produced anterior end. The hinge has a small triangular internal cartilage pit. Members of the genus have a narrow hinge line, a short resilium, and right valves that either have a single oblique anterior tooth, or both an anterior and posterior tooth; the latter being much weaker if present, except in species which are relatively more equilateral. Mysella have limited external sculpture, and are most commonly under in size, with some species reaching a length of .
The genus was first described in 1877 by George French Angas.
Mysella has a global distribution. The earliest known fossils of the genus date to the Paleocene, and have been found in Alabama and Texas in the United States.
Species within the genus Mysella include: