Daisy Outdoor Products (known primarily as Daisy) is an American airgun manufacturer known particularly for their lines of BB guns. It was formed in 1882 initially as the Plymouth Iron Windmill Company in Plymouth, Michigan, to manufacture steel windmills, and from 1888 started bundling BB-caliber air guns with each windmill purchase as a sales promotion. With the unrivaled popularity of their 1888-model Daisy BB Guns, the company changed the name to Daisy Manufacturing Company in 1895 and switched their business to solely producing air guns for sale. Throughout the 20th century, Daisy has been known as a company that makes and sells BB guns and pellet youth rifles. Their Red Ryder BB Gun is perhaps the best known and longest production item, which has been featured in many TV shows and movies since its introduction in the spring of 1940.

The company started in 1882 by watchmaker and inventor Clarence Hamilton in Plymouth, Michigan, as the Plymouth Iron Windmill Company, to manufacture a type of vaneless windmills that Hamilton invented in 1880. By the mid-1880s the business was struggling, as transporting the heavy steel windmills by wagons throughout the southern part of Michigan, northern Indiana, and throughout Ohio was impractical. In January 1888 the company board met to consider closing the factory, but the motion to liquidate failed by one vote — that of general manager Lewis Cass Hough.

Around the corner from the windmill company, Hamilton also operated the Plymouth Air Rifle Company, to compete with the Markham "Challenger" — a new type of wooden spring-powered airgun shooting BB-size round shot invented by Captain William F. Markham (though some argued that the real inventor was George W. Sage) in 1886 — manufactured by the Markham Air Rifle Company just across the Chesapeake and Ohio Railway. On March 6, 1888, Hamilton approached the windmill company board with an all-metal airgun design of his own and sought to use the factory blast furnaces to mold and stamp the metal parts necessary to build his gun. General manager Lewis Hough test fired the gun and exclaimed, "Boy, it's a daisy!", and the new gun was named the "Daisy BB Gun". The board of the Windmill Company then decided to offer the gun as a bundled premium item to every farmer who purchased a windmill.

This began many years of intense competition between Plymouth and Markham, who responded by introducing their metal "Chicago" (1888) and "King" (1890) model BB guns. However, Plymouth's marketing strategy was much better, as by 1900, 15% of their sales revenue was being spent on posters and magazines space, with the net result of such intensive promotion being to make Daisy virtually a household word, while Markham paid little effort on advertising. The Daisy BB Guns continued to outsell its competitors, and by 1895 its sales and popularity had grown to the point that the Plymouth Company ceased the manufacture of windmills, began producing airguns exclusively, and the board voted to change the company name to Daisy Manufacturing Company.

In 1901, Daisy introduced a 500-shot lever-action rifle (predating Markham's by nine years), and special guns were even built to shoot streams of water at Masonic initiations. Perhaps the most famous model was the Little Daisy, Model 20, which was made continuously with only three model changes between 1908 and 1937 and at times sold for less than fifty cents. Daisy's continued market lead eventually led the Markham management to give up competing and quietly sold out to two Daisy executives in 1916, and Captain Markham himself moved to California. The acquired Markham Company changed its name to King Air Rifle Company in 1928, and continued to manufacture the Markham "King" Model air rifle until 1935, before ceasing operation all together in the 1940s.

In 1958, the company moved the corporate offices and manufacturing facilities from Plymouth to Rogers, Arkansas.

In 1993, Daisy was acquired by the private equity firm Charter Oak Partners. The Plymouth factory was demolished in 2005 and replaced with a condominium complex called Daisy Square. One wall of the factory building remained in front of the complex until its demolition on November 18, 2013. The wall had been free-standing since the factory was torn down, and was supposed to be built into an apartment building, but the wall was not included in the completed building. The Daisy Administration building, on Main Street, is still standing and has become an office complex and restaurant. In 2016, Daisy was sold by Charter Oak to another private equity firm, Bruckmann, Rosser, Sherrill & Co., who combined it with Gamo Outdoor.

Daisy is best known for their inexpensive youth BB guns, modeled after lever-action rifles. Perhaps the most famous of these is the Red Ryder model, which is still in production today, despite the fact that the Red Ryder comic strip was canceled in 1963. These simple smoothbore, spring-air BB guns fire at low velocities, and are marketed to children ages 10 and over. In addition to the spring air BB guns, Daisy also markets a line of multi-pump pneumatic rifles capable of firing pellets or BBs to the same age group.