A pencil sharpener (also known as a pencil sharpener or topper in Ireland) is a device for sharpening the point of a pen by scraping off worn surfaces. The pencil sharpener can be operated manually or by an electric motor. For many pencil sharpeners, there is usually a shell around them, which can be removed to pour pencil scraps into the dustbin.

Before developing a special pencil sharpener, sharpen the pencil with a knife. The pencil sharpener makes the task much easier and the results more uniform. Some special types of pencils, such as carpenters' pencils, are usually sharpened with a knife because of their flat shape. However, since the 2000's, the fixed blade device with rotatable collar has been put on the market.

Bernard lassimone, a French mathematician, applied for the first patent (French patent 2444) of the pencil sharpener in 1828, but it was not until 1847 that Thierry des estivaux, a French mathematician, invented the recognizable modern form of the pencil sharpener. The first American pencil sharpener was patented by Walter K. foster of Bangor, Maine in 1855. John Lee love is an African American in faliver, Massachusetts, who invented a portable pencil sharpener. The design is simple, including a hand crank and a compartment for storing shavings. In 1897, the pencil sharpener was patented, and there is no evidence that it has ever been produced, at least since 1917, an electric pencil sharpener for office use.

In May 2011, tourism officials in Logan, Ohio, displayed hundreds of pencil sharpeners collected by Pastor Paul Johnson, who died in 2010, at their regional reception center. World War II veteran Johnson collected more than 3400 sharpeners in a shed outside his home in carbon hill, Southeast Ohio. In the late 1980s, after his wife gave him some pencil sharpeners as gifts, he began collecting them. He divided them into several categories, including cats, Christmas and Disneyland. The oldest is 105.

The so-called "prism" pencil sharpener, also known as "manual" or "pocket" pencil sharpener in the United States, has no separate moving parts, and is usually the smallest and cheapest common pencil sharpener on the market. The simplest common varieties are small rectangular prisms or blocks, only about 1? 5/8？ Dimensions are 7 / 16 inch (2.5 × 1.7 × 1.1 cm). The block pencil sharpener consists of a combined point cone that is aligned with the cylindrical pencil alignment guide hole into which the pencil is inserted. A sharp blade is installed so that its sharp edge only cuts into the forming cone. Insert the pencil into the pencil sharpener and rotate it while keeping the pencil sharpener stationary. The body of a sharpener is usually contoured, raised, or slotted to make small pieces easier to hold, usually made of aluminum, magnesium, or rigid plastic.