Ingersoll-Rand plc (NYSE: IR) is an American global diversified industrial manufacturing company formed in 1905 by the merger of Ingersoll-Sergeant Drill Company and Rand Drill Company, rival companies that had each been founded in 1871. The company is incorporated in Dublin, Ireland, but has its headquarters in Davidson, North Carolina. Ingersoll-Rand has been a constituent of the S&P 500 Index since 2010, replacing Pactiv Corporation on 16 November 2010 (it had previously been in the S&P 500 Index until it was replaced by Quanta Services in June 2009).

In 1871, Simon Ingersoll (1818–1894) founded Ingersoll Rock Drill Company in New York, and in 1888 it combined with Sergeant Drill to form Ingersoll Sergeant Drill Company. Also in 1871, brothers Addison Rand (1841–1900) and Jasper Rand, Jr. (1837–1909) established Rand Drill Company with its main manufacturing plant in Tarrytown, New York. Rand drills cleared New York's treacherous Hell Gate channel and were used in the construction of water aqueducts for New York City and Washington, D.C., and tunnels in Haverstraw and West Point, New York, and in Weehawken, New Jersey. In 1905 Ingersoll-Sargeant Drill Company merged with the Rand Drill Company to form Ingersoll Rand. Ingersoll Rand has grown largely by acquisition since that time.

In the 1920s, Ingersoll Rand supplied diesel engines for locomotives built by both General Electric and ALCO.

In October 2002, shareholders voted to move the company's incorporation to Bermuda to capitalize on the savings on U.S. corporate income taxes on products sold overseas. Moving the company on paper cost only US$27,000 per year with a tax savings estimated at US$40 million. Ingersoll Rand announced in March 2009 its intention to relocate its offices from Bermuda to Ireland, a decision which shareholders approved in a vote.

In July 2004, the Drilling Solutions business was sold to the Swedish company Atlas Copco. This included factories in United States, China, Japan making above ground rotary blasthole and deephole drilling machines. Atlas Copco purchased the company for US$225M. Drilling Solutions was a legacy business from the company's founding.

In May 2007, the company announced it was looking into a sale or spin-off of its Bobcat, utility equipment, and attachments divisions. With this divestiture, Ingersoll Rand was left with the industrial technologies, climate control technologies, and security technologies sectors. This completed the transformation from the diversified machinery label to a diversified industrial company.

In February 2007, Volvo, a Swedish truck and construction equipment manufacturer, announced its agreement to buy the road construction equipment division of Ingersoll-Rand for $1.3 billion in cash to expand its operations in the United States. The road unit manufactures and sells asphalt paving equipment, compaction equipment, milling machines and construction-related material handling equipment and generated net revenues of approximately $850 million for 2006. The sale included manufacturing facilities in Pennsylvania, Germany, China and India, as well as 20 distribution and service facilities in the United States. The business employs approximately 2,000 people worldwide.

On 30 July 2007, Ingersoll Rand announced that the utility and attachment businesses had been sold to Doosan Infracore, part of the South Korean chaebol Doosan, for US$4.9 billion.

On 17 December 2007, Ingersoll Rand announced an offer to purchase HVAC supplier Trane, in a stock and cash transaction. The purchase was approved by Trane's stockholders, and the unit became a part of the climate control technologies business, which is divided into commercial and residential business units, each reporting directly to the chairman. The sale was completed on 5 June 2008.

On 2 December 2013, Ingersoll Rand completed the spinoff of its security hardware sector into a standalone business named Allegion, which maintains commercial and residential security hardware brands such as Schlage, Von Duprin, LCN, Bricard, Interflex, Normbau and CISA.

In August 2014, it was announced that Ingersoll-Rand would acquire the centrifugal compression unit of Cameron International for $850 million.

In September 2017, the Asthma and Allergy Foundation of America and Allergy Standards Limited announced that the Trane CleanEffects™ whole home air cleaner from Ingersoll Rand has earned the Asthma and Allergy Friendly Certification. This is the first whole home air cleaner to receive this Certification.

Ingersoll Rand's corporate headquarters are in Swords, Fingal, County Dublin, Ireland. Its American headquarters are in Davidson, North Carolina. Its European headquarters are in Sint-Stevens-Woluwe, Zaventem, Belgium. Its Asia headquarters are in Tower B of City Center of Shanghai in Shanghai, People's Republic of China.

The company's list of brands and subsidiaries include: