A number of societies and clubs organize various activities among the students. Of these, the Student Union, which is a formal society, is the most important, and looks after the general welfare of the students. Each faculty has a Faculty Student Union. The Faculty Unions form an umbrella organization called the Peradeniya Students Union (PSU). All undergraduates are members of the Student Union and have the right to vote in the annual elections. There are other societies where the membership is based on either interests or academic discipline. The interest-based societies are mostly Inter Faculty associations. The following are some student societies where students can pursue their interests.

1. Buddhist Brotherhood
2. Hindu Students' Society
3. Inter Faculty Students' Centre Society
4. Music Society
5. Muslim Majlis (Islamic Brotherhood)
6. Photographic Society
7. Sarasavi Sanvada Kendraya (University Debating Society)
8. Sinhala Natya Mandalaya (Sinhala Dramatic Society)
9. Tamil Society
10. University Dramatic Society
11. University Explorers' Club
12. University Film Society
13. University Gandharva Sabha (Oriental Music Society)
14. University Newman Society (Catholic Brotherhood)
15. World University Service, Peradeniya

1. Commerce Society
2. Curia Historica (History Society)
3. Diploma Students Union
4. Economics Society
5. English Literary Association
6. Geographical Society
7. Pali and Buddhist Students Society
8. Political Science Society
9. Sinhala Society
10. Society of Archaeology
11. Sociological Association