Family name Thayananthan (Thayananthan 
) , all around the world, is a rare cognomen. The family name Thayananthan is habitual in Sri Lanka, where it is quite a rare surname, Switzerland, where it is a rare surname, and Australia, where it is a very rare surname. Measured by absolute frequency, it is the most numerous in Sri Lanka, the United Kingdom, and Canada. Also, Thayananthan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Thayananthan | Canada, United Kingdom, Malaysia, Sri Lanka, Australia |