Henry Bradley Plant (1819-1899) war ein US-amerikanischer Eisenbahnmagnat und Pionier der touristischen Erschließung des westlichen Florida.

Plant stand von seiner Familie her das Studium an einer angesehenen Universität offen, er entschied sich jedoch dafür, sich in der Transportindustrie von der Pike an hinauf zu arbeiten. Plant erwies sich insbesondere als erfolgreich bei der Organisation von Paketexpressdiensten und erreichte in relativ jugendlichem Alter führende Angestelltenpositionen. Aufgrund ihrer schwachen Gesundheit wurde 1853 Plants Gattin Elizabeth empfohlen, sich vornehmlich im Süden aufzuhalten. Dies und vorherige Geschäftsverbindungen mit den Südstaaten führte dazu, dass sich Henry B. Plant ab den 1870er Jahren für das darniederliegende Eisenbahnwesen in den im Sezessionskrieg besiegten Bundesstaaten interessierte und bankrotte Linien billig aufzukaufen begann. Plant förderte auch den Tourismus in den Westlichen Küstengebieten des Bundesstaats Florida durch den Bau von Eisenbahnhotels, ähnlich wie das Henry Morrison Flagler etwa gleichzeitig an der Ostküste Floridas tat. Plants 1891 errichtetes Tampa Bay Hotel mit seinen 13 maurischen Türmen stellt hier eine Art Gegenstück zu Flaglers Ponce de Leon Hotel in St. Augustine dar. Seit 1933 beherbergt das heute unter Denkmalschutz stehende Gebäude die University of Tampa. Auch ein Henry B. Plant gewidmetes Museum ist darin untergebracht.

Henry Bradley Plant (1819-1899), was involved with many transportation projects, mostly railroads, in the U.S. state of Florida. Eventually he owned the Plant System of railroads which became part of the Atlantic Coast Line Railroad. Plant City, located near Tampa, was named after him.

Henry Bradley Plant was founder of the Plant System of railroads and steamboats. He was born in Branford, Conn., the son of Betsey (Bradley) and Anderson Plant, a farmer in good circumstances. He was the descendant of John Plant who probably emigrated from England and settled at Hartford, Conn., about 1639. When the boy was six, his father died. Several years later his mother married again and took him to live first at Martinsburg, N.Y., and later at New Haven, Conn., where he attended a private school. His grandmother, who hoped to make a clergyman of him, offered him an education at Yale College, but, impatient to begin an active career, he got a job as captain's boy, deck hand, and man-of-all-work on a steamboat plying between New Haven and Hartford.

Among his various duties was the care of express parcels. This line of business, hitherto neglected, he organized effectively, and, when it was taken over by the Adams Express Company and later transferred from steamboats to railroads, he went along with it. After a few years he was put in charge of the old York office of the company. In 1853 his wife, Ellen Elizabeth (Blackstone) Plant, to whom he had been married in 1842, was ordered South for her health. Several months spent near Jacksonville, then a tiny hamlet, impressed the shrewd Yankee with the possibilities of the future development of Florida.

The next year he became the general superintendent of the Adams Express Company for the territory south of the Potomac and Ohio rivers. In the face of great difficulties he successfully organized and extended express service in this region, where transportation facilities, although rapidly growing, were still deficient and uncoordinated. At the approach of the Civil War the directors of Adams Express, fearing the confiscation of their Southern properties, decided to transfer them to Plant. With the Southern stockholders of the company he organized in 1861 the Southern Express Company, a Georgia corporation, and became president. His company acted as agent for the Confederacy in collecting tariffs and transferring funds. In 1863, following a serious illness, he took an extended vacation in Europe, and he returned by way of Canada.

After the war, the railroads of the South were practically ruined and many railroads went bankrupt in the depression of 1873. In this situation he found his opportunity. Convinced of the eventual economic revival of the South, he bought at foreclosure sales in 1879 and 1880 the Atlantic and Gulf Railroad and the Charleston and Savannah Railroad. With these as a nucleus he began building along the southern Atlantic seaboard a transportation system that twenty years later included fourteen railway companies with 2,100 miles of track, several steamship lines, and a number of important hotels. In 1882 he organized, with the assistance of Northern capitalists, among whom were H.M. Flagler, M.K. Jesup, and W.T.Walters, the Plant Investment Company, a holding company for the joint management of the various properties under his control. He reconstructed and extended several small railroads so as to provide continuous service across the state, and by providing better connections with through lines to the North he gave Florida orange growers quicker and cheaper access to Northern markets. Tampa, then a village of a few hundred inhabitants, was made the terminus of his southern Florida railroad and also the home port for a new line of steamships to Havana.

For the accommodation of winter visitors he built in Tampa, in the style of a Moorish palace, an enormous hotel costing $2,500,000. The hotel was called the Tampa Bay Hotel and was famous for its fanciful Moorish and Victorian architecture. The hotel now serves as the main building for the University of Tampa and houses the Henry B. Plant Museum. Another large, Victorian-style hotel established by Plant during the 1890s was the Belleview Biltmore near Clearwater, Florida.

The subsequent growth in wealth and population of Florida and other states tributary to the Plant System made its founder one of the richest and most powerful men in the South. A good physical inheritance, preserved by temperate habits, made it possible for Henry Plant to keep working until almost eighty years of age.

Henry Plant built eight hotels. His most prized was the Tampa Bay Hotel, built at a cost of $3 million, said to be an attempt to compete with fellow industrialist Henry M. Flagler, who was developing Florida's east coast.

In his will he attempted to prevent the partition of his properties to the value of about $10,000,000 by forming a trust for the benefit of a great-grandson, but the will was contested by his widow and declared invalid under the laws of the state of New York. This decision made possible the consolidation of his railroads with other properties to form the Atlantic Coast Line Railroad, today a key portion of the Florida operations of CSX Transportation.

Plant's son, Morton Freeman Plant (1852–1918), was vice-president of the Plant Investment Company from 1884 to 1902 and attained distinction as a yachtsman. He was part owner of the Philadelphia baseball club in the National League, and sole owner of the New London club in the Eastern League. Of the younger Plant's many gifts to hospitals and other institutions the most notable were the three dormitories and the unrestricted gift of $1,000,000 to the Connecticut College for Women. His former 1905 mansion on Fifth Avenue in New York City is now the home of Cartier.