| Thachanadan | |
| States: | India |
| Speakers: | 3,000 |
| Date: | 2004 survey |
| Ref: | e18 |
| Familycolor: | Dravidian |
| Fam2: | Southern |
| Fam3: | Southern I |
| Fam4: | Tamil–Kannada |
| Fam5: | Tamil–Kota |
| Fam6: | Tamil–Toda |
| Fam7: | Tamil–Irula |
| Fam8: | Tamil–Kodava–Urali |
| Fam9: | Tamil–Malayalam |
| Fam10: | Malayalamoid |
| Ancestor: | Old Tamil |
| Ancestor2: | Middle Tamil |
| Iso3: | thn |
| Glotto: | thac1235 |
| Glottorefname: | Thachanadan |
Thachanadan is a Southern Dravidian language spoken by a Scheduled tribe of India. Dissimilar to other Dravidian languages, its most likely affinities are to Mullu Kurumba, with which it has 66-72% lexical similarity.