The Shadwell forgeries, most commonly known as Billy and Charley Forgeries, or "Billys and Charleys", but also called Shadwell Dock forgeries, were mid-19th-century forgeries of medieval lead and lead-alloy artefacts. The name "Billy and Charley" derives from William "Billy" Smith and Charles "Charley" Eaton, who were responsible for the large-scale manufacture of the objects between 1857 and 1870. Some leading antiquarians were fooled by the forgeries, despite their being crudely made, due to Smith and Eaton's limited metalworking skills and illiteracy.

Today, Billy and Charleys are sometimes viewed as examples of naïve art or outsider art. Some museums hold collections of them and they have become sought-after collectible items in their own right. It has been alleged that modern fake Billy and Charleys are in circulation, although it is uncertain if this is true.

Little is known of the lives of William Smith (dates unknown) and Charles Eaton (c.1834–1870) except that when young they were mudlarks; individuals that made a living by searching the mudflats of the River Thames at low-tide, seeking any item of value. They lived in Rosemary Lane (now called Royal Mint Street) in what is now part of the London Borough of Tower Hamlets.

In 1844 or 1845, Smith came into contact with an antique dealer, William Edwards. Eaton met Edwards some years later. Edwards came to view the pair as "his boys" and frequently bought from them items of interest they found while mudlarking.

In 1857 Smith and Eaton began to manufacture counterfeit artefacts. During their career, they are estimated to have made between 5,000 and 10,000 items. These displayed a variety of designs, including pilgrim badges, ampullae, statuettes, portable shrines, coins, medallions and ornamental spearheads. Initially these were made from lead or pewter, but copper-lead alloys were later applied. The items were cast using plaster of Paris moulds, into which a design was engraved by hand. They were then given the appearance of age by being bathed in acid and coated with river mud.

The commonest productions were medallions, around 2 to 4 inches (5 to 10 cm) in diameter. These had crude depictions of knights in armour, crowned kings or religious figures. They often carried inscriptions, but as Smith and Eaton were illiterate, these were meaningless jumbles of letters and symbols. To give the appearance of age, many of the items also carried dates between the 11th century and the 16th century. However the dates were inscribed using Arabic numerals which only came into use in England during the 15th century and so are anachronistic.

Between 1857 and 1858 Smith and Eaton sold about 1,100 of their forgeries to Edwards for a total of about £200. He, in turn, described them as "the most interesting relics I have met with for years". Smith and Eaton claimed the source of the steady stream of antiquities was the large-scale excavations then taking place as part of the construction of London's Shadwell Dock. Edwards showed samples to another antique dealer, George Eastwood, who bought many from Edwards before buying further supplies directly from Smith and Eaton, making these products his principal stock in trade. Eastwood advertised the items as a "A remarkable curious and unique collection of leaden signs or badges of the time of Richard II", He sold them to several customers, who were willing to pay highly for them; some were bought by individuals on behalf of the British Museum, although the keepers there were suspicious about their authenticity.

By 1858 Henry Syer Cuming, the secretary of the British Archaeological Association and Thomas Bateman, a wealthy landowner in the Derbyshire Peak District, who was also a keen antiquarian, archaeologist and collector, had become aware of the trade in these artefacts. They immediately suspected them to be forgeries, emanating from a single source, and corresponded with a view to exposing the objects as such.