The Persian alphabet (Persian: الفبای فارسی, romanized: Alefbâ-ye Fârsi), also known as the Perso-Arabic script, is the right-to-left alphabet used for the Persian language. This is like the Arabic script with four additional letters: پ چ ژ گ (the sounds 'g', 'zh', 'ch', and 'p', respectively), in addition to the obsolete ڤ that was used for the sound /β/. This letter is no longer used in Persian, as the [β]-sound changed to [b], e.g. archaic زڤان /zaβɑn/ > زبان /zæbɒn/ 'language'. Although the sound /β/ (ڤ) is written as "و" nowadays in Farsi (Dari-Parsi/New Persian), it is different to the Arabic /w/ (و) sound, which uses the same letter.

It was the basis of many Arabic-based scripts used in Central and South Asia. It is used for both Iranian and Dari: standard varieties of Persian; and is one of two official writing systems for the Persian language, alongside the Cyrillic-based Tajik alphabet.

The script is mostly but not exclusively right-to-left; mathematical expressions, numeric dates and numbers bearing units are embedded from left to right. The script is cursive, meaning most letters in a word connect to each other; when they are typed, contemporary word processors automatically join adjacent letter forms. Persian is unusual among Arabic scripts because a zero-width non-joiner is sometimes entered in a word, causing a letter to become disconnected from others in the same word.

The Persian alphabet is directly derived and developed from the Arabic alphabet. The Arabic alphabet was introduced to the Persian-speaking world after the Muslim conquest of Persia and the fall of the Sasanian Empire in the 7th century. Following this, the Arabic language became the principal language of government and religious institutions in Persia, which led to the widespread usage of the Arabic script. Classical Persian literature and poetry were affected by this simultaneous usage of Arabic and Persian. A new influx of Arabic vocabulary soon entered the Persian language. In the 8th century, the Tahirid dynasty and Samanid dynasty officially adopted the Arabic script for writing Persian, followed by the Saffarid dynasty in the 9th century, gradually displacing the various Pahlavi scripts used for the Persian language earlier. By the 9th-century, the Perso-Arabic alphabet became the dominant form of writing in Greater Khorasan.

Under the influence of various Persian Empires, many languages in Central and South Asia that adopted the Arabic script use the Persian Alphabet as the basis of their writing systems. Today, extended versions of the Persian alphabet are used to write a wide variety of Indo-Iranian languages, including Kurdish, Balochi, Pashto, Urdu (from Classical Hindustani), Saraiki, Panjabi, Sindhi and Kashmiri. In the past the use of the Persian alphabet was common amongst Turkic languages, but today is relegated to those spoken within Iran, such as Azerbaijani, Turkmen, Qashqai, Chaharmahali and Khalaj. The Uyghur language in western China is the most notable exception to this.

During the Soviet period many languages in Central Asia, including Persian, were reformed by the government. This ultimately resulted in the Cyrillic-based alphabet used in Tajikistan today. See: Tajik alphabet § History.

Below are the 32 letters of the modern Persian alphabet. Since the script is cursive, the appearance of a letter changes depending on its position: isolated, initial (joined on the left), medial (joined on both sides) and final (joined on the right) of a word. These include 28 letters of the Arabic alphabet, in addition to 4 other letters.

The names of the letters are mostly the ones used in Arabic except for the Persian pronunciation. The only ambiguous name is he, which is used for both ح and ه. For clarification, they are often called hâ-ye jimi (literally "jim-like he" after jim, the name for the letter ج that uses the same base form) and hâ-ye do-češm (literally "two-eyed he", after the contextual middle letterform ـهـ), respectively. There are eight Persian letters that are mainly used in Arabic or foreign loanwords and not in native words: ث, ح, ذ, ص, ض, ط, ظ, ع and غ. These eight letters are also commonly used only in proper names. Unlike Arabic, the Persian language does not have pharyngealization at all. Although the letter غ is mainly used in Arabic loanwords, there are some native Persian words with this letter: آغاز, زغال, etc. The pronunciation of these letters in Persian can differ from their pronunciation in Arabic. For example, the letter ث is pronounced as /s/ in Persian, while it is pronounced as /θ/ in Arabic.