Its history dates back over 2000 years, and was a flourishing trading center from the early Sangam days.

There is a memorial at Rayanur dedicated to the warriors who lost their lives in the fight against the British in the Anglo-Mysore Wars.

A new district was formed on 30 September 1996 by bifurcating Karur, Kulithalai and Manapparai Taluks of Tiruchirappalli district, which comprises the present-day Aravakkurichi, Manmangalam, Pugalur, Karur, Krishnarayapuram, Kulithalai, Musiri, Kadavur and Manapparai Taluks.

According to 2011 census, Karur district has a population of 1,064,493 with a sex-ratio of 1,015 females for every 1,000 males, much above the national average of 929.

Town Panchayats in Karur include Aravakurichi, Pallapatti, Punjaipugalur, TNPL Pugalur (Kagithapuram), Puliyur, Uppidamangalam, Palaya Jeyankonda Cholapuram, Krishnarayapuram, Marudur, and Nangavaram.

The Major villages are : K.Paramathi, Thennilai, Thogaimalai, Pavithram, Chinnadhrapuram, Punnam chathiram, Mayanur, Lalapet, Vangal, Nerur, Ayyar malai, Velliyanai, Esanatham.

The main crops are paddy, banana, sugarcane, beetle leaf, grams & pulses, tapioca, kora grass, groundnuts, oilseeds, tropical vegetables, garland flowers, and medicinal herbs.

[9] Allied industries like ginning and spinning mills, dyeing factories, weaving etc., employs at around 450,000 people in and around Karur.

The weaving industry came to Karur from Kerala and has earned a reputation for its high-quality hand-loom products today.

It produces 230,000 tons of Printing & writing paper and consumes 1 million tonnes of bagasse every year, providing more employment options.

Bharat Petroleum Corporation Limited (BPCL) has its receiving terminal and retails distribution plant at Attur, near Karur.

The Karur belt also produces some very good amethyst, cat's eyes, feldspar, moonstones, aquamarines, sapphires, jasper and beryl.

[citation needed] Apart from these, there are 3 SIDCO industrial estates, a textile park namely, The Karur Textile Park Limited and many private contributing sectors like LGB Retreads, Rolon Chains, VKA Polymers, Shobika Impex, VKA Diary etc., have their headquarters or production units in Karur District.

In response to the epidemic, a massive district-level communication campaign (DLCC) was launched in 2006 by the USAID-funded APAC-VHS project in the district.

In 2007, the district received its own ART (Antiretroviral drug therapy) Centre, located at the Government General Hospital.

There are two national highways: NH-44 (North South Corridor Road (Kashmir to Kanyakumari)) Srinagar – Kanyakumari and NH-67 (Nagapattinam – Trichy – Karur – Coimbatore – Gudalur), which connect with other major towns such as Chennai, Erode, Tiruppur, Pollachi, Hosur, Tuticorin, Dindigul, Theni, Oddanchatram, Dharapuram, Palani, Tanjore, Karaikudi, Kumbakonam, Kochi, and Pondicherry.