| Theni | |
| Settlement Type: | Neighbourhood |
| Nickname: | Gateway to highland |
| Pushpin Map: | India Tamil Nadu |
| Pushpin Label Position: | Foot of Western Ghats, Kerala border. |
| Pushpin Map Caption: | Theni, Tamil Nadu, India |
| Coordinates: | 10.0079°N 77.4735°W |
| Subdivision Type: | Country |
| Subdivision Name: |  India |
| Subdivision Type1: | State |
| Subdivision Name1: | Tamil Nadu |
| Subdivision Type2: | District |
| Subdivision Name2: | Theni |
| Government Type: | Municipality |
| Governing Body: | Theni Allinagaram Municipality |
| Leader Title1: | Chairman |
| Leader Name1: | S Murugesan |
| Leader Title2: | Commissioner |
| Leader Name2: | S Nagarajan |
| Unit Pref: | Metric |
| Elevation M: | 339 |
| Population Total: | 202,100 |
| Population As Of: | 2011 |
| Population Footnotes: | [1] |
| Population Density Km2: | auto |
| Demographics Type1: | Languages |
| Demographics1 Title1: | Tamil, Telugu, Malayalam, English, Kannada |
| Timezone1: | IST |
| Utc Offset1: | +5:30 |
| Postal Code Type: | PIN |
| Postal Code: | 625531 |
| Area Code: | 04546 |
| Area Code Type: | Telephone code |
| Registration Plate: | TN 60, TN 60Z |
| Blank1 Name Sec1: | Distance from State Capital Chennai |
| Blank1 Info Sec1: | 498km (309miles) southwest |
| Blank1 Name Sec2: | Climate |
| Blank1 Info Sec2: | Average and moderate cool at winter (Köppen) |
| Demographics1 Info1: | Tamil |
| Blank2 Name Sec2: | Precipitation |
| Blank2 Info Sec2: | 658mm |
| Blank3 Name Sec2: | Avg. summer temperature |
| Blank3 Info Sec2: | 39.5°C |
| Blank4 Name Sec2: | Avg. winter temperature |
| Blank4 Info Sec2: | 25.8°C |
Theni is a valley town situated in the Indian state of Tamil Nadu at the foothills of the Western Ghats. It is the headquarters of the Theni district, located at a distance of 70km from Madurai. It is known for the large-scale trading of garlic, cotton, cardamom, grapes, bananas, mango and chilli. It hosts the second largest weekly market in Tamil Nadu and the fourth largest in South India.
For drinking water project in Madurai, for which the Asian Development Bank funds ₹1,653.21 crore under the AMRUT scheme, the Madurai Municipal Corporation has a proposal for a mega plan to draw water from Periyar River and treat it in Theni and distribute to all the neighbourhoods in Madurai City through pumping stations.[2]