A leaf blower is a gardening tool that propels air out of a nozzle to move yard debris such as leaves. Leaf blowers are usually powered by two-stroke engine or an electric motor, but four-stroke engines were recently introduced to partially address air pollution concerns. Leaf blowers are typically self contained handheld units, or backpack mounted units with a handheld wand. The latter is more ergonomic for prolonged use.

Some units can also suck in leaves and small twigs via a vacuum, and shred them into a bag. In that role it is called a blower vac.

The leaf blower was invented by Dom Quinto in the late 1950s. It was originally introduced to the United States as part of an agricultural chemical sprayer. Shortly thereafter manufacturers discovered that many consumers were removing the chemical dispensing parts from the device, leaving only the blower behind. Manufacturers then saw the potential of their invention as a common lawn and garden maintenance tool. Drought conditions in California facilitated acceptance of the leaf blower as the use of water for many garden clean-up tasks was prohibited. By 1990, annual sales were over 800,000 in the U.S., and the tool had become a ubiquitous gardening implement.

Other functions beyond the simple use of garden maintenance have been demonstrated by Richard Hammond on the Brainiac television series, in which a man sized hovercraft was constructed from a leaf blower. Being both portable and able to generate wind speeds of between 140-270 mph and air volumes of 14 cbm per minute, the leaf blower has many potential uses in amateur construction projects.

Pollution from gasoline-powered grounds-keeping equipment in general is a source of air pollution.US emission standards specifically limit emissions from small engines. Today small engines release up to 90% less hydrocarbons than previous generations.

Noise pollution is also a concern with leaf blowers. Soon after the leaf blower was introduced into the U.S., its use was banned in two California cities, Carmel-by-the-Sea in 1975 and Beverly Hills in 1978, as a noise nuisance. There are currently twenty California cities that have banned leaf blowers, sometimes only within residential neighborhoods and usually targeting gasoline-powered equipment. Another 80 cities have ordinances on the books restricting either usage or noise level or both. Other cities have discussed and rejected leaf blower bans. Nationwide, three states, Arizona, Hawaii and New Jersey, have considered laws at the state level, and five other states have at least one city with a leaf blower ordinance.In response to criticisms manufactures have significantly reduced the noise of modern leaf blowers. Many models now produce less than 65 dB following the measurement guidelines of ANSI B175.2-2002. In 2005 Echo announced that most leaf blowers were 75% more quiet than 10 years ago.