The Odia (formerly Oriya) script is used for writing the Odia language, the official language of the Indian state of Orissa, as well as a number of Dravidian and Munda minority languages spoken in that region. It is also used in Orissa for transcribing Sanskrit texts. The earliest inscriptions in the Odia language have been dated to 1051 AD, written in the Kalinga script from which modern Odia writing is derived.

Like the other Brahmic scripts used in India, the Odia script is written from left to right and is based on the orthographic syllable called akṣara. An akṣara represents either a lone vowel or a consonant with a vowel attached. Each vowel sound can be written with one of two letters; used at the beginning of a word it is written with an independent vowel letter, but when it follows a consonant it is written with a dependent vowel diacritic which attaches above, below, beside or flanking both sides of the consonant letter. Consonant letters inherently contain a following [ɔ] vowel (transcribed a) unless they are modified with a vowel diacritic indicating a different vowel, or a halanta symbol silencing the vowel entirely.

Consonant clusters can be written in several ways. Some combinations use a special non-decomposable ligature, or conjunct, for example jnya. Others are written using the halanta symbol to silence the vowel in the first member of the cluster. Alternatively, clusters can be written using half- or joining forms of all but one letter in the cluster. In some cases the first member is reduced to a half-form and attached to the second, for example in the cluster dbha; in other cases the second member is reduced and attached to the first, as in dgha. The orthographic syllable does not necessarily correspond to the phonological syllable in words containing consonant clusters.

Ligatures composed of an independent vowel and a consonant are generally not used, with the exception of the letter wa which is a combination of o and ba and is sometimes used for writing the sound [w] in loan words.

The script is largely phonetic, that is, the pronunciation of a word can be deduced from its spelling, but there are a few phonological processes that alter the sound of a written letter. For example, the letters da and dha are pronounced as [ɽ] [ɽh] respectively when used between two vowels. A subscript dot is often written below the letter to indicate this change. So the word 'Odia' is written o + (da + dot + i diacritic) + a.

As with many of the Brahmic scripts, the anusvara symbol can be used to indicate a nasal pronounced at the same place of articulation as the following stop, as in the cluster [ŋkɔ], when written anusvara + ka. However, these clusters can also be written using special conjunct letters; a distinct letter also exists for representing the sound [ŋkɔ].

There is one script-specific punctuation mark, isshar, which is used before the name of a person who is deceased.