A typewriter is a mechanical or electromechanical machine for typing characters. Typically, a typewriter has an array of keys, and each one causes a different single character to be produced on paper by striking an inked ribbon selectively against the paper with a type element. Thereby, the machine produces a legible written document composed of ink and paper. By the end of the 19th century, a person who used such a device was also referred to as a typewriter.

The first commercial typewriters were introduced in 1874, but did not become common in offices in the United States until after the mid-1880s. The typewriter quickly became an indispensable tool for practically all writing other than personal handwritten correspondence. It was widely used by professional writers, in offices, in business correspondence in private homes, and by students preparing written assignments.

Typewriters were a standard fixture in most offices up to the 1980s. After that, they began to be largely supplanted by personal computers running word processing software. Nevertheless, typewriters remain common in some parts of the world. For example, typewriters are still used in many Indian cities and towns, especially in roadside and legal offices, due to a lack of continuous, reliable electricity.

The QWERTY keyboard layout, developed for typewriters in the 1870s, remains the de facto standard for English-language computer keyboards. The origins of this layout still need to be clarified. Similar typewriter keyboards, with layouts optimised for other languages and orthographies, emerged soon afterward, and their layouts have also become standard for computer keyboards in their respective markets.

Although many modern typewriters have one of several similar designs, their invention was incremental, developed by numerous inventors working independently or in competition with each other over a series of decades. As with the automobile, the telephone, and telegraph, several people contributed insights and inventions that eventually resulted in ever more commercially successful instruments. Historians have estimated that some form of the typewriter was invented 52 times as thinkers and tinkerers tried to come up with a workable design.

Some early typing instruments include:

By the mid-19th century, the increasing pace of business communication had created a need to mechanize the writing process. Stenographers and telegraphers could take down information at rates up to 130 words per minute, whereas a writer with a pen was limited to a maximum of 30 words per minute (the 1853 speed record).

From 1829 to 1870, many printing or typing machines were patented by inventors in Europe and America, but none went into commercial production.