A tittle is a small distinguishing mark, such as a diacritic or the dot over an i. It first appeared in Latin manuscripts in the 11th century, to distinguish the letter i from strokes of nearby letters. Although originally a larger mark, it was reduced to a dot when Roman-style typefaces were introduced.

In the modern Turkish alphabet, it is an actual diacritical mark distinguishing two different phonemes, appearing even on top of capital letters: I / ı, with the absence of a tittle, representing the sound [ɯ], and İ / i, with the inclusion of a tittle, representing [i].