Sclerosis or sclerotization (also spelled sclerosus in the names of a few disorders) is a hardening of tissue and other anatomical features; it may refer to:
- in medicine, Sclerosis (medicine)
- in zoology, a process which hardens animal exoskeletons by adding proteins such as resilin and sometimes mineral salts such as calcium carbonate
- in botany, a process which hardens plant tissue by adding fibers and sclereids, resulting in sclerenchyma
- Cyberbrain Sclerosis, a fictional disease introduced in Ghost in the Shell: Stand Alone Complex. The disease is characterized by hardening of the brain tissues precipitated by the cyberization process.
- In economics, see: Eurosclerosis