A wrinkle is a ridge or crease of a surface. It usually refers to folds on fabric or clothes, or on the skin of an organism.

Skin wrinkles typically appear as a result of aging processes or, temporarily, as the result of pro-longed (more than a few minutes) submersion in water.

Treatments and products (including Anti-aging creams) promising to reduce, remove or prevent age-related wrinkles is big business in many industrialised countries. Despite great demand, most such products and treatments have not been proven to give lasting or major positive effects.