I is a vowel of Indic abugidas. In modern Indic scripts, I is derived from the early "Ashoka" Brahmi letter after having gone through the Gupta letter . As an Indic vowel, "I" comes in two normally distinct forms: 1) as an independent letter, and 2) as a vowel sign for modifying a base consonant. Bare consonants without a modifying vowel sign have the inherent "A" vowel.

Aryabhata used Devanagari letters for numbers, very similar to the Greek numerals, even after the invention of Indian numerals. The "I" sign was used to modify a consonant's value ×10², but the independent vowel letter did not have an inherent value by itself.

There are three different general early historic scripts - Brahmi and its variants, Kharoṣṭhī, and Tocharian, the so-called slanting Brahmi. I as found in standard Brahmi, was a simple geometric shape, with variations toward more flowing forms by the Gupta . Like all Brahmic scripts, Tocharian I has an accompanying vowel mark for modifying a base consonant. In Kharoṣṭhī, the only independent vowel letter is for the inherent A. All other independent vowels, including I are indicated with vowel marks added to the letter A.

The Brahmi letter , I, is probably derived from the altered Aramaic Ayin , and is thus related to the modern Latin O and Greek Omicron. Several identifiable styles of writing the Brahmi I can be found, most associated with a specific set of inscriptions from an artifact or diverse records from an historic period. As the earliest and most geometric style of Brahmi, the letters found on the Edicts of Ashoka and other records from around that time are normally the reference form for Brahmi letters, with vowel marks not attested until later forms of Brahmi back-formed to match the geometric writing style.

The Tocharian letter is derived from the Brahmi . Unlike some of the consonants, Tocharian vowels do not have a Fremdzeichen form.

The Kharoṣṭhī letter I is indicated with the vowel mark . As an independent vowel, I is indicated by adding the vowel marks to the independent vowel letter A .

I (इ) is a vowel of the Devanagari abugida. It ultimately arose from the Brahmi letter , after having gone through the Gupta letter . Letters that derive from it are the Gujarati letter ઇ, and the Modi letter 𑘂.

The Devanagari script is used to write the Hindi language, Sanskrit and the majority of Indo-Aryan languages. In most of these languages, इ is pronounced as [i]. Like all Indic scripts, Devanagari vowels come in two forms: an independent vowel form for syllables that begin with a vowel sound, and a vowel sign attached to base consonant to override the inherent /ə/ vowel.