| Thyagi Annamalai Nagar | |
| Settlement Type: | Town panchayat |
| Pushpin Map: | India Tamil Nadu |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location in Tamil Nadu, India |
| Coordinates: | 12.22°N 79.11°W |
| Subdivision Type: | Country |
| Subdivision Name: |  India |
| Subdivision Type1: | State |
| Subdivision Name1: | Tamil Nadu |
| Subdivision Type2: | District |
| Subdivision Name2: | Tiruvannamalai |
| Leader Title: | Chairman |
| Leader Name: | ravi kumar (dmk) |
| Unit Pref: | Metric |
| Area Total Km2: | 16.3 |
| Elevation M: | 171 |
| Population Total: | 22987 |
| Population As Of: | 2012 |
| Population Density Km2: | auto |
| Demographics Type1: | Languages |
| Demographics1 Title1: | Official |
| Demographics1 Info1: | Tamil |
| Timezone1: | IST |
| Utc Offset1: | +5:30 |
| Area Code Type: | Telephone code |
| Area Code: | 91-4175 |
| Registration Plate: | TN 25 |
| Blank1 Name Sec1: | Lok Sabha constituency |
| Blank1 Info Sec1: | thiruvannamlai |
| Blank2 Name Sec1: | Vidhan Sabha constituency |
| Blank2 Info Sec1: | thiruvannamalai city |
| Blank1 Name Sec2: | Climate |
| Blank1 Info Sec2: | moderate (Köppen) |
| Blank2 Name Sec2: | Avg. summer temperature |
| Blank2 Info Sec2: | 41°C |
| Blank3 Name Sec2: | Avg. winter temperature |
| Blank3 Info Sec2: | 18°C |
Thyagi annamalai nagar or Thyagi annamalaipuram or T.A.Nagar is a 1st-grade town panchayat constructed as a 3rd-grade town panchayat in 1994 and upgraded to 2nd grade in 2002 (at this time Lakshmipuram is carved out and joined into Gandhinagar) and 1st grade in 2007.Thyagi Annamalai nagar has declined in population in census due to carving to its sub-area Laksmipuram because main T.nagar comprises population of 19,000 and Lakshmipuram has a population of 11,000 in 2001 census totally. 30,000 is the population of Thyagi Anamalai Nagar. But in 2011, T. Anagar had its own population of 23,000.
T.nagar having population of over 23,000 providing sub urban to Tiruvannamalai urbanity. it comes under Tiruvannamalai urban agglomerations on Pondicherry road NH 66. Thiruvannamali junction and Thiruvannamalai central are located in the limit of T.nagar town panchayat.