Niagara Falls Hydraulic Power & Manufacturing Company was an American company, based in Niagara Falls, New York that was the first company to generate hydroelectric power from Niagara Falls in 1882. The company built upon several predecessor companies efforts to construct a canal used for hydraulic mill power. In 1918, the company merged with Niagara Falls Power Company, which later became Niagara Mohawk and in 2002 was acquired by National Grid plc.

In 1805, "Porter, Barton & Company," which comprised Augustus Porter, Peter Porter, Benjamin Barton, and Joseph Anim, purchased the Niagara River and the American Falls from New York at a public auction. The purchase also included the water rights from above the upper rapids to below the Falls. The company portaged goods by land from Lake Erie to Lewiston on the Niagara River, then shipped them east on Lake Ontario. When the Erie Canal opened in 1825, it made the portage obsolete and plans to develop Niagara Falls suffered. Augustus proposed a hydraulic mill canal in 1847 and offered the right of way for the canal to any person ready to build it, but the Porter brothers died before interest in the project led to construction.

In 1852, Caleb Smith Woodhull and his associates purchased the land and the water rights from the heirs of the Porter brothers with the intention to build a canal, and in 1853 formed the "Niagara Falls Hydraulic Company." A grant was obtained from the owners of a strip of land 100 ft. wide extending from a point above the upper rapids to the high bank below the Falls. The company started with the construction of the canal in 1853 but stopped after sixteen months because construction costs of the canal significantly exceeded estimates and the company went bankrupt.

In 1856, Stephen N. Allen bought the company, which was renamed the "Niagara Falls Water Power Company." The company completed the entrance and river portion of the canal by 1857, with the exception of a narrow extension at the south end of the basin which was completed in 1881.

In 1860, Horace H. Day purchased the company and renamed it the "Niagara Falls Canal Company." At an investment of $1.5 million, (equivalent to $44,292,000 in 2024) the canal was finally completed in 1861, but could not be used because of the American Civil War. After completing the canal project, it was idle until 1875 when the canal's first customer, Charles B. Gaskill's "Cataract City Milling Company", was using the water of the canal to power the milling company's flour grist mill.

In 1877, as the company had only attracted one client, it declared bankruptcy and was auctioned off. The company interests were bought for $71,000 (equivalent to $2,096,000 in 2024) by Jacob F. Schoellkopf, who in 1878 formed the "Niagara Falls Hydraulic Power and Manufacturing Company" to use the canal.

After the transfer of the property, Schoellkopf finished the excavating, but the canal remained idle for a few years. The work on the power plant began and the canal was enlarged in 1892. By 1896, power plant number two had been completed and was supplying power to different factories above Niagara Falls. Many additions and extensions were made to the original plant, and company began to work on a new plant, called plant number three, that when completed, was separate from the original plant around six or eight hundred feet to the north. The workings of the Hydraulic company were entirely below the first Upper Steel Arch Bridge.

Plant number two, which was one 100 ft. by 176 ft. in dimensions, generated an average of 34,000 continuous horsepower. The entire fall of the water in the canal from the forebay to the tailrace is 210 ft. The power canal, which taps the river at a point above Port Day, and runs throughout the city to a point below the Upper Steel Arch Bridge, furnished a steady supply of water year round. Just below Port Day is the beginning of the rapids, with a fall of more than 50 ft. in three-quarters of a mile. By cutting across a bend in the river the canal comes out at the cliff below the bridge the entire distance being about 4,400 ft. Built before the era of industrial production of alternating current, the electrical plant generated direct-current electricity, and only provided it within a range of two miles from the plant.