In typography and lettering, a sans-serif, sans serif (/ˈsæn(z) ˈsɛrɪf/), gothic, or simply sans letterform is one that does not have extending features called "serifs" at the end of strokes. Sans-serif typefaces tend to have less stroke width variation than serif typefaces. They are often used to convey simplicity and modernity or minimalism. For the purposes of type classification, sans-serif designs are usually divided into these major groups: § Grotesque, § Neo-grotesque, § Geometric, § Humanist, and § Other or mixed.

Sans-serif typefaces have become the most prevalent for display of text on computer screens. On lower-resolution digital displays, fine details like serifs may disappear or appear too large. The term comes from the French word sans, meaning "without" and "serif" of uncertain origin, possibly from the Dutch word schreef meaning "line" or pen-stroke. In printed media, they are more commonly used for display use and less for body text.

Before the term "sans-serif" became standard in English typography, a number of other terms had been used. One of these terms for sans-serif was "grotesque", often used in Europe, and "gothic", which is still used in East Asian typography and sometimes seen in typeface names like News Gothic, Highway Gothic, Franklin Gothic or Trade Gothic.

Sans-serif typefaces are sometimes, especially in older documents, used as a device for emphasis, due to their typically blacker type color.

For the purposes of type classification, sans-serif designs are usually divided into three or four major groups, the fourth being the result of splitting the grotesque category into grotesque and neo-grotesque.

This group features most of the early (19th century to early 20th) sans-serif designs. Influenced by Didone serif typefaces of the period and sign painting traditions, these were often quite solid, bold designs suitable for headlines and advertisements. The early sans-serif typefaces often did not feature a lower case or italics, since they were not needed for such uses. They were sometimes released by width, with a range of widths from extended to normal to condensed, with each style different, meaning to modern eyes they can look quite irregular and eccentric.

Grotesque typefaces have limited variation of stroke width (often none perceptible in capitals). The terminals of curves are usually horizontal, and many have a spurred "G" and an "R" with a curled leg. Capitals tend to be of relatively uniform width. Cap height and ascender height are generally the same to produce a more regular effect in texts such as titles with many capital letters, and descenders are often short for tighter line spacing. They often avoid having a true italic in favor of a more restrained oblique or sloped design, although at least some sans-serif true italics were offered.

Examples of grotesque typefaces include Akzidenz-Grotesk, Venus, News Gothic, Franklin Gothic, IBM Plex and Monotype Grotesque. Akzidenz Grotesk Old Face, Knockout, Grotesque No. 9 and Monotype Grotesque are examples of digital fonts that retain more of the eccentricities of some of the early sans-serif types.