| Thenmathur | |
| Settlement Type: | panchayat town |
| Pushpin Map: | India Tamil Nadu |
| Pushpin Label Position: | left |
| Pushpin Map Caption: | Location in Tamil Nadu, India |
| Coordinates: | 12.2°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: | mrs. Vijitha kumaran (dmk) |
| Unit Pref: | Metric |
| Area Total Km2: | 16.3 |
| Elevation M: | 171 |
| Population Total: | 5120 |
| Population As Of: | 2012 |
| Population Density Km2: | auto |
| Demographics Type1: | Languages |
| Demographics1 Title1: | Official |
| Demographics1 Info1: | Tamil |
| Timezone1: | IST |
| Utc Offset1: | +5:30 |
| Postal Code Type: | PIN |
| Postal Code: | 606 609 |
| 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 |
Thenmathur or EAC township is a township in Tiruvannamalai in Tiruvannamalai District in Tamil Nadu State. It serves as a suburban to its main city Tiruvannamalai. Thenmathur is 2.6 km from its Taluk Main Town Tiruvannamalai. Thenmathur is located 2.9 km from its District Main City Tiruvannamalai. It is located 158 km from its State Main City Chennai.
Nearby towns and panchayats with distance are Tiruvannamalai (2.9 km), So.Kilnachipattu (3.4 km), Chinnakangiyanur (3.8 km), Nallavanpalayam (4.3 km). Towns nearby Tiruvannamalai (2.6 km), Thandrampet (15.3 km), Thurinjapuram (19.9 km), Keelpennathur (21.8 km).
Tamil Nadu north zone's second famous deemed Arunai Engineering College and university is here. It is the second largest after Vit spreads over 14.5 km2 from Thenmathur to Veraiyur.
Thenmathur has a population of over 5000 providing sub urban to Tiruvannamalai urbanity. It comes under Tiruvannamalai urban agglomerations on Tirukovilur Road (Chitoor–Cudllore road) NH 234A. There are three railway stations for Thenmathur at Tirukovilur railway route: