Budesonide is a corticosteroid for the treatment of asthma, non-infectious rhinitis (including hay fever and other allergies), and for treatment and prevention of nasal polyposis. Additionally, it is used for inflammatory bowel disease. It is marketed by AstraZeneca as a nasal inhalation with the brand name Rhinocort, as an oral inhalation with the brand name Pulmicort, and as an enema with the brand name Entocort. It is also sold in combined with formoterol (Oxis) in a single inhaler, with the brand name Symbicort.

Budesonide has a high first pass metabolism. It has efficacy in the terminal ileum and the right colon. It has a lower incidence of systemic manifestations than similar medications.