[1] The Semitic sound value of Qôp was /q/ (voiceless uvular stop), and the form of the letter could have been based on the eye of a needle, a knot, or even a monkey with its tail hanging down.

[a] In common with other glyphs derived from the Proto-Sinaitic script, the letter has been suggested to have its roots in Egyptian hieroglyphs.

[5][6] In an early form of Ancient Greek, qoppa (Ϙ) probably came to represent several labialized velar stops, among them /kʷ/ and /kʷʰ/.

[13] In Turkey between 1928 and 2013 the use of the letter Q, alongside X and W, was banned from official government documents, such as street signs and brochures.

[18] A common method among type designers to create the shape of the Q is by simply adding a tail to the letter O.

[15] This print tradition was alive and well until the 19th century, when long-tailed Qs fell out of favor; even recreations of classic typefaces such as Caslon began being distributed with only short Q tails.

[15] The long-tailed Q had fallen out of use with the advent of early digital typography, as many early digital fonts could not choose different glyphs based on the word that the glyph was in, but it has seen something of a comeback with the advent of OpenType fonts and LaTeX, both of which can automatically typeset the long-tailed Q when it is called for and the short-tailed Q when it is not.

[25] In the Identifont database, the distribution of Q tails is:[26]Some type designers prefer one "Q" design over another: Adrian Frutiger, famous for the airport typeface that bears his name, remarked that most of his typefaces feature a Q tail that meets the bowl and then extends horizontally.

When handwritten, or as part of a handwriting font, the descender of the "q" sometimes finishes with a rightward swash to distinguish it from the letter "g" (or, particularly in mathematics, from the digit "9").