Tortoiseshell can refer to:
- tortoiseshell material, made primarily from the shell of the Hawksbill turtle
- Tortoiseshell cat
- a pattern used in clothing and jewellery
- tortoiseshell butterflies, brush-footed butterflies (Nymphalidae) in the genera Aglais and Nymphalis
- "Tortoiseshell", a song by The Boo Radleys which appeared on their EP Every Heaven