A fess is a heraldic charge.
Fess or FESS may also refer to:
- Simeon D. Fess (1861-1936), American politician and educator, Congressman and Senator from Ohio
- Fess Parker (1924-2010), American actor
- Professor Longhair (1918-1980), blues singer and pianist also known as "Fess"
- Fess, nickname of Charlie Johnson (bandleader) (1891-1959), American jazz bandleader and pianist
- Fess Williams (1894-1975), American jazz musician
- Functional endoscopic sinus surgery, also brandname of a simple saline solution for sinus irrigation
- Fess Hotel, Madison, Wisconsin, on the National Register of Historic Places
- Fess Ferenc, a fictional character from Brian Lumley's Necroscope (series) novels
- FESS, an Open Source Enterprise Search Server based on Elasticsearch