L.E. McCullough notes that the oldest surviving whistles date from the 12th century, but that, "Players of the feadan are also mentioned in the description of the King of Ireland's court found in the Brehon Laws dating from the 3rd century A.D." The Tusculum whistle is a 14cm whistle with six finger holes, made of brass or bronze, found with pottery dating to the 14th and 15th centuries; it's currently in the collection of the Museum of Scotland.
The term "penny whistle" was coined on the streets of Dublin in the late 1500's because of the whistles' prevalence among the beggars and vagabonds in Ireland. The word "tin-whistle" was also coined as early as 1825. but neither word seems to have been common until the 20th century. The first record of tin-plate whistles dates back to 1825 in Britain.
The first factory-made "tinwhistles" were produced by Robert Clarke (? - 1882) in Manchester and later New Moston, England. Up to 1900, they were also marketed as "Clarke London Flageolets" or "Clarke Flageolets". The whistle's fingering system is similar to that of the six hole, simple system, "Irish flute" ("simple" in comparison to Boehm system flutes). The six hole, diatonic system is also used on baroque flutes and other folk flutes, and was of course well known before Robert Clarke began producing his tin whistles circa 1843. Clarke's first whistle, the Meg, was pitched in high A and was later made in other keys suitable for Victorian parlor music. The company showed the whistles in The Great Exhibition of 1851.
In the second half of the 19th century, some flute manufacturers such as Barnett Samuel and Joseph Wallis also sold whistles. These had a cylindrical brass tube. Like many old whistles, they had lead fipple plugs; since lead is poisonous, caution should be exercised before playing an old whistle.
The Generation whistle was introduced in the first half of the 20th century, and also featured a brass tube with a lead fipple plug. The design was updated somewhat over the years, most notably the substitution of a plastic fipple for the lead plug design.
While whistles have most often been produced in higher pitches, the "low" whistle is not unknown historically. The Museum of Fine Arts, Boston has in its collection an example of a 19th century low whistle from the famous Galpin collection. During the 1960s revival of traditional Irish music the low whistle was "recreated" by Bernard Overton at the request of Finbar Furey.