Play-Dohs exact makeup is a trade secret, but it is primarily a mixture of wheat flour, water, mineral oil (which provides the smooth texture), salt, a drying agent such as borax (which deters mould), an alum-based hardening agent, colourings and perfume.

It is non-toxic, non-staining, and soluble in soapy water. When kept in a sealed container, Play-Doh remains pliable, but when exposed to air it hardens in a few days. However, because it tends to crack during hardening, it is not ideal for projects one wants to save.

Play-Doh was invented by Noah and Joseph McVicker in 1956 and awarded U.S. Patent 3,167,440 in 1965. One of many common products invented by accident, it was meant as a wallpaper cleaner, but Joseph's sister, a kindergarten teacher, started letting her students use it as a moulding compound for art projects, since clay was too hard and messy. It was marketed by toy manufacturer Rainbow Crafts, and first sold at the Woodward & Lothrop department store in Washington, D.C.

Play-Doh is available in several different colours and sizes, and has a distinctive smell and texture. Over 900 million pounds (410 million kg) have been sold so far. The product is now owned by American toy giant Hasbro.

In 2006, the distinctive Play-Doh smell was turned into a limited-edition fragrance by the Demeter Fragrance Library to celebrate the product's 50th birthday. There is also a national Play-Doh Day on September 18.

While Play-Doh is registered, there are many different recipes for generic play doughs with various differences, such as edibility, odour, and colour.