Johnson Controls International Plc is a multinational conglomerate headquartered in Cork, Ireland that produces automotive parts such as batteries and electronics and HVAC equipment for buildings. It employs 170,000 people in more than 1,300 locations across six continents. As of 2016 it was listed 242nd in the Fortune Global 500; in 2017 it became ineligible for the Fortune 500, as it was headquartered outside the U.S.

The company was formed via the merger of U.S. company Johnson Controls with Tyco International, announced on January 25, 2016. The merger led to the avoidance of U.S. taxes of its foreign market operations and a financial windfall for the CEO.

In 1883, Warren S. Johnson, a professor at the State Normal School in Whitewater, Wisconsin, received a patent for the first electric room thermostat. His invention helped launch the building control industry and was the impetus for a new company. Johnson and a group of Milwaukee investors incorporated the Johnson Electric Service Company in 1885 to manufacture, install and service automatic temperature regulation systems for buildings. After Johnson's death in 1911, the company decided to focus on its temperature control business for nonresidential buildings. The company was renamed Johnson Controls in 1974.

On November 21, 2005, Johnson Controls Inc. said it must restate financial results for fiscal years 2003 and 2004 and the first three quarters of fiscal 2005. The changes would have no impact on net income, earnings per share or the financial position as previously reported. During the 2008-2009 recession, the company president Keith Wandell lobbied Congress for a bailout of the companies Johnson supplied. The Johnson Controls plant in Lakeshore, Ontario closed in late March 2010 and the property was sold. In 2013, Stephen Roell retired and Alex Molinaroli took his position as CEO and chairman of the board.

On October 31, 2016, the former Johnson Controls Automotive Experience division was spun off as a separate, publicly traded company, Adient plc, and began trading on the New York Stock Exchange. In March 2017, it was announced that Scott Safety, its safety gear business, would be bought by 3M for $2 billion.

On September 1, 2017, George Oliver was appointed Chairman and CEO, an acceleration by 6 months from the original plans.

In January 2016, Johnson Controls merged with Tyco International to create a company headquartered in Cork, Ireland. The new company is called Johnson Controls International Plc.

Hillary Clinton condemned the company for wanting to escape U.S. taxes through the merger after having "begged" the government for financial help in 2008. The Johnson deal, termed "outrageous" by Fortune magazine, qualifies as a "super inversion" because Tyco shareholders will own 44% of the company, thus avoiding penalties that the United States Department of the Treasury has imposed on other inversion deals.

The firm estimated it would save about one hundred and fifty million dollars in a year by avoiding American taxes..

In 1982, Johnson Controls enacted what it called a "fetal protection policy", which denied women the right to work on the battery production line because of the potential harm to a fetus they might conceive. Women were allowed to work on the production line only if they could prove that "...their inability to bear children had been medically documented." In April 1984, the United Auto Workers sued Johnson Controls on behalf of three employees. These employees were Mary Craig, who had chosen to be sterilized to avoid losing her job, Elsie Nason, a 50-year-old divorcee, who had suffered a loss of compensation when she was transferred from a high paying job that exposed her to lead, and Donald Penney, who had been denied a request for a leave of absence for the purpose of lowering his blood lead levels because he intended to become a father. The case was argued before the Supreme Court on October 10, 1990 and was decided on March 20, 1991. The Court ruled in favor of the plaintiffs. This was a landmark ruling because it affirmed that "...it is no more important for the courts than it is for individual employers to decide whether a woman's reproductive role is more important to herself and her family than her economic role."

The company’s operations are segmented into four business units: Building Efficiency, Global WorkPlace Solutions, Power Solutions and Automotive Experience.

The Building Efficiency business unit designs, produces, installs and services heating, ventilation and air conditioning systems, industrial refrigeration, building management systems, fire and security systems and mechanical equipment for commercial and residential buildings. The brands produced under this business unit are York, TempMaster, Metasys, Panoptix, Frick and Sabroe. This unit also works with organizations to reduce the energy consumption and operating costs of their buildings. This includes retrofitting existing buildings such as the Empire State Building and working on maximizing efficiency in new construction such as the Burj Khalifa in Dubai. Building Efficiency is the company’s longest-running business unit, dating to 1885 when Johnson founded the Johnson Electric Service Company after patenting the electric thermostat in 1883. As of 2012, the business unit operated from 700 branch offices in more than 150 countries.

Johnson Controls was one of the defendants in a multimillion-dollar federal court lawsuit in San Juan, Puerto Rico in a case where 98 people perished and 140 were injured in a fire at the DuPont Plaza Hotel and its casino on New Year’s Eve, December 31, 1986. The plaintiffs claimed that Johnson Controls sold and installed an energy management system that failed to give early warning of the fire. After nine months of trial, the company and its energy management system were absolved of blame when the court issued a directed verdict. When this trial was completed the plaintiffs had accumulated approximately $220,908,549.00 in damages as a result of various settlements and a jury verdict against some other defendants.

The Global WorkPlace Solutions business unit provides outsourced facilities management services globally. It also manages corporate real estate on behalf of its customers including acquiring and disposing of property, administering leases, and managing building related projects such as equipment replacements. On September 23, 2015, CBRE, Inc. purchased the Global Workplace Solutions business unit, retaining the name "Global Workplace Solutions".

The Power Solutions business unit designs and manufactures automotive batteries for passenger cars, heavy and light duty trucks, utility vehicles, motorcycles, golf carts and boats. It supplies more than one third of the world’s lead-acid batteries to automakers and aftermarket retailers including Wal-Mart, Sears and BMW. Lead acid battery brands produced under this business unit include OPTIMA, Heliar, LTH, and VARTA automotive batteries. This part of the company also manufactures Lithium-ion cells and complete battery systems to power hybrid and electric vehicles such as the Ford Fusion and Daimler’s S-Class 400. Additionally, it manufactures Absorbent Glass Matt (AGM) and Enhanced Flooded Batteries (EFB) batteries to power Start-Stop vehicles such as the Chevy Malibu and Ford Fusion. As of 2012, the business unit operated from 60 locations worldwide.

The Automotive Experience business unit supplies automotive seating, interiors and electronics to automakers. It is one of the largest suppliers of car interiors in the world. The seating division designs and manufactures automotive seats and supplies them on a just-in-time schedule. It also designs and manufactures seating components, including mechanisms, tracks, structures foams, fabrics and trim, making Johnson Controls the largest automotive seat supplier in the world. A separate interiors division produces overhead systems, headliners, door panels, instrument panels, and overhead and floor consoles for automotive interiors. Additionally, an electronics division designs and manufactures analog and digital instrument clusters, infotainment systems and hands free electronics. Brands produced under this business unit include RECARO automotive seats and Keiper. As of 2012, the business unit operated from 240 locations worldwide. On June 6, 2015, Johnson Controls had scheduled an exit from the automotive seating business to concentrate on core business of building ventilation and automotive batteries. On January 12, 2016 Johnson Controls announced that its remaining Automotive Experience holdings will spin-off and become Adient Plc. This will be finalized on October 1, 2016, and begin to be publicly traded on the NYSE as ticker symbol ADNT on October 3, 2016.