The hair dryer has been around since the 1890s, but the contraptions people first used to dry their hair are a world away from the sleek, modern devices we know today. We do know that a French hairdresser invented the first hair dryer, but the circumstances surrounding his invention are unclear.
Alexandre F. Godefroy is credited with inventing the first hot air-blast hair dryer, probably in 1890. All over the Internet we find this man, usually with his name misspelled, having been inspired by the powered vacuum cleaner's warm exhaust and attaching the hose to the exhaust instead of the suction area. Since the first patents for gasoline-powered, motor-driven cleaners with a vacuum were taken out in 1899 and 1901, this claim for inspiration is questionable. Before this, vacuum cleaners were hand-cranked or were manual carpet sweepers. Some sources, including an article at pbs.org, say the bonnet of Godefroy's air-blast dryer was attached to the chimney pipe of a gas stove.
The earliest illustration of a hair dryer comes from the 1900 Encyclopedie Larousse Illustree, showing a large apparatus that looks like a precursor to later beauty salon hood dryers--except the hair is apparently being pulled into the machine rather than blown forward. The device appears to have a power cord, and also has a hand crank. It is unlikely that this is the hair dryer attributed to Godefroy. A resource below links to the image at Wikimedia Commons.
That machine obviously would be quite cumbersome for casual use. In the 1930s, seated hood dryers became common in salons, with beehive-shaped helmets that stood nearly 2 feet tall. Households did not start commonly including hair dryers in their preferred appliances until more lightweight portable machines came available in the 1950s, with a smaller hood or a flexible bonnet.
Inventors in the 1920s did their best to develop portable, handheld blow dryers. These dryers were made of steel and zinc with wooden handles, and weighted over 0.907kg. They also only produced 100 watts of heat and thus did not dry hair very well. These factors prevented the dryers from becoming much of a success. Lighter, plastic, handheld blow dryers with higher wattage finally became available in the 1950s and took off in popularity over the next decade.
Besides Godefroy, other European hair care pioneers also used heat to style hair. Frenchman Marcel Grateau developed the technique of thermal waving using hot air, tongs and irons to create hair curls and waves. This method is still known as Marcel waving. German hairstylist Charles Nessler created the first permanent wave in 1905, using curlers attached to electric wires for heat and covered in borax paste. This technique took 12 hours and was extremely expensive. Godefroy, Grateau and Nessler provide the foundation for our current hairstyling world with its wide variety of hair dryers and curling irons, and permanent waves that only require a 2-hour stop at the salon.