Quin may refer to:
- Quin (name), including a list of people with the name
- Quin, colloquially, one of a set of quintuplets, a multiple birth of five individuals
- Quin (Sigilverse), a fictional planet
- Quin, County Clare, a village in County Clare, Ireland
- QUIN, quinolinic acid, a dicarboxylic acid with a pyridine backbone
- Quin House, nickname for Algonquin Club, Boston, Massachusetts