A monospaced font, also called a fixed-width or non-proportional font, is a font whose letters each occupy the same amount of space. This contrasts to variable-width fonts, where the letters differ in size to one another.

The first monospaced typefaces were designed for typewriters, which could only move the same distance forward with each letter typed. This also meant that monospaced fonts need not be typeset like variable width fonts and were, arguably, easier to deal with.

A proportional typeface displays glyphs using varying widths, while a non-proportional or fixed-width or monospaced typeface uses fixed glyph widths.

Most people generally find proportional typefaces nicer-looking and easier to read, and thus they appear more commonly in professionally published printed material. For the same reason, GUI computer applications (such as word processors and web browsers) typically use proportional fonts. However, many proportional fonts contain fixed-width figures so that columns of numbers stay aligned.