Lamellae is a term for several very different biological and material structures. It may mean:

• Lamellae (zoology), various gill-shaped structures found within the respiratory organs or bone or nacre of an animal.
• Lamellae (mycology), the "gills" or leaf-shaped hymenophore structures beneath the pileus of an agaric.
• Lamellae (materials), various layered structures within geological, biological, or synthetic materials, for example mica and graphite.
• Lamellae (cell biology), cell structures associated with cellular motility.