A malar rash (from Latin mala ‘jaw, cheek-bone’), also called butterfly rash, is a medical sign consisting of a characteristic form of facial rash. It is often seen in lupus erythematosus. More rarely, it is also seen in other diseases, such as pellagra, dermatomyositis, and Bloom syndrome.

A malar rash of lupus is red or purplish and mildly scaly. It has the shape of a butterfly, and involves the bridge of the nose. Notably, the rash spares the nasolabial folds of the face, which contributes to its characteristic appearance. It is usually macular with sharp edges, and not itchy.

There are many conditions which can cause rashes with a similar appearance to a malar rash. A malar rash is present in approximately 46–65% of people with lupus.