Pajčin (Serbian Cyrillic: Пајчин) is a Serbian surname, a patronymic of Pajo, itself a diminutive of Pavle (Paul). A Pajčin family lives in Gubin, Bosnia and Herzegovina. It may refer to:
- Mirko Pajčin (born 1966), known as "Baja Mali Knindža", Serbian folk singer.
- Ksenija Pajčin (1977–2010), Serbian pop singer and dancer.