Genesee & Wyoming Inc. is an American short-line railroad holding company that owns or maintains interests in 120 railroads throughout five countries (the United States, Canada, Australia, Belgium, Netherlands and the United Kingdom), and operates more than 15,500 miles (24,900 km) of owned and leased track, with more than 3,300 miles (5,300 km) under additional track-access arrangements. The company had its roots in the Class III Genesee and Wyoming Railroad, which began in 1899.

Genesee and Wyoming Railroad, predecessor of Genesee & Wyoming Inc., was purchased out of bankruptcy in 1899 by Edward L. Fuller. At that time, the railroad was operating as a 14.5-mile long (23.3 km) single-track line serving a single customer, a salt mine owned by Fuller in Retsof, NY. It was still operating the same line for the salt mine when Mortimer B. Fuller III, great grandson of Edward L. Fuller, purchased the railroad in 1977. The holding company, Genesee & Wyoming Railroad Inc., was organized during the same year, and the railroad became its subsidiary.

With deregulation of the rail industry by the Staggers Rail Act of 1980, railroads began disposing of unprofitable routes. Genesee & Wyoming acquired several of these short line railroads, scattered across the United States, from 1985 to 1996. Its acquisitions began including railroads in other countries in 1997.

In November 1997 Genesee & Wyoming purchased the South Australian freight operations of Australian National and rebranded the operation Australian Southern Railroad.

In October 2000 Australian Railroad Group, a 50/50 joint venture between Genesee & Wyoming and Wesfarmers, were the successful bidder for the Westrail freight business in Western Australia. As part of the joint venture agreement, ownership of Australian Southern Railroad passed to Australian Railroad Group.

In July 2003, the Carolina Coastal Railway, operated by G&W subsidiary Rail Link, Inc., was sold to Main Line Rail Management, Inc.

On May 26, 2005, G&W announced that it has agreed to purchase the railroad operations of Rail Management Corporation (RMC). G&W paid $243 million in cash and assume $1.7 million in company debt to gain control of 14 short line railroads from RMC across the southeastern United States, as of June 1, 2005.

As of the close of 2005, Genesee and Wyoming had 2,330 employees in North America. That year, Hurricane Stan wiped out several miles of Genesee & Wyoming track in Mexico. In 2006, the Mexican government agreed to pay 75 percent of the rebuilding costs, or $15 million, to reconstruct the track.

In June 2006 the Australian Railroad Group joint venture was broken up with the Western Australian above rail operation sold to QR National and the below rail infrastructure to Babcock & Brown in a $974 million (A$1.55 billion) deal. At the same time Wesfarmers sold its 50% share in the South Australian operation back to Genesee & Wyoming Inc for $15 million (A$22 million). The operation was rebranded Genesee & Wyoming Australia.

Also in 2006, Genesee & Wyoming elected to write off most of the value of its Bolivian operation, on fears that the Bolivian government would soon nationalize privately held railroads there. Genesee & Wyoming remains an investor in Empresa Ferroviaria Oriental, S.A.

In June 2010 Genesee & Wyoming, through a subsidiary holding company, paid A$334 million to acquire the operational rights to and the leasehold of the Tarcoola to Darwin Railway from the Asia Pacific Transport Consortium, and the operational rolling stock of FreightLink. This 1,400 miles (2,300 km) rail line was the longest the company has leased.

On 2 August 2011, Genesee & Wyoming announced that it planned to purchase the Arizona Eastern Railway from Iowa Pacific Holdings for US$90.1 million, with the deal expected to be completed by the end of the year. The deal was closed on 1 September 2011.

On July 23, 2012, Genesee & Wyoming agreed to purchase RailAmerica Inc. (RA), the short-line railroad holding company controlled by Fortress Investment Group LLC (FIG), for $1.39 billion to combine North America’s two largest short-line and regional rail operators.

On February 24, 2015, Genesee & Wyoming announced that it has agreed to acquire approximately 95% of the shares of Freightliner Group Limited.

On August 15, 2016, Genesee & Wyoming announced that intended to acquire the Providence & Worcester Railroad, which operates in Massachusetts, Rhode Island, Connecticut, and New York, for $126 million. The deal was approved by Providence & Worcester shareholders in October, and the Surface Transportation Board approved the acquisition in December.

On February 7, 2017, Genesee & Wyoming announced that it had reached an agreement to purchase the Heart of Georgia Railroad, subject to regulatory approval.

Genesee & Wyoming Inc. owns controlling interests in 122 freight railroads, either directly or through subsidiaries, which are organized into 11 operating regions. These subsidiaries include Rail Link, Inc. (1996), Genesee & Wyoming Canada, Inc. (1997), Emons Railroad Group (2002), CAGY Industries (2008), and Summit View, Inc. (2008). In 2005 G&W acquired the properties formerly owned by the Rail Management Corporation.

Rail Link, Inc. (reporting mark RLIX), a subsidiary of Genesee & Wyoming Inc., provides industrial switching and related customer logistics services. Rail Link, headquartered in Jacksonville, Florida, serves industrial customers at 30 locations in 11 states and operates 26 short line railroads (including the Commonwealth Railway, and Yorkrail). Rail Link railroads serve 10 major U.S. ports.