1 Company in Charlotte, North Carolina

Honeywell's history is a corporate jigsaw puzzle: it began as a Minneapolis heating-control company (the Honeywell thermostat was invented in 1906), merged with an aerospace company, bought a defense electronics maker, and over a century assembled a portfolio spanning thermostats, jet engines, barcode scanners, and safety equipment. The result is one of America's most diversified industrial conglomerates. The modern Honeywell is organized around four businesses: aerospace (avionics, engines, and aircraft systems for commercial and defense customers — roughly a third of revenue), building automation (HVAC controls, fire and security systems for commercial buildings), industrial automation (process control systems for refineries and factories, plus warehouse automation and barcode scanning under the Honeywell brand), and safety & productivity solutions (personal protective equipment, gas detection, and rugged mobile computers). Headquartered in Charlotte, North Carolina, with about 95,000 employees and annual revenue near US$37 billion, Honeywell is in the middle of a breakup: in 2024 it announced plans to split into three independent companies — aerospace, automation, and advanced materials — arguing the pieces are worth more apart. For industrial buyers, Honeywell remains the supplier whose name appears on everything from a refinery's control room to a worker's safety harness.