The name Mehdi originates from Arabic and has its roots in the word "Mahdi", which means "the rightly guided one" or "the divinely guided one". This name has a significant religious and cultural significance in Islamic traditions, particularly in Shia Islam.

The name Mehdi is closely associated with the concept of the Mahdi, a messianic figure in Islamic eschatology who is believed to appear at the end of times to establish justice and peace on Earth. In Shia Islamic theology, the Mahdi is considered the 12th and final Imam, a descendant of Prophet Muhammad through his grandson Husayn ibn Ali.

The earliest recorded use of the name Mehdi can be traced back to the 7th century CE, when it was given to some of the descendants of the Prophet Muhammad and his family members. One of the most notable historical figures with this name was Abu al-Qasim Muhammad ibn al-Hasan al-Mahdi, who was the third Abbasid caliph and ruled from 775 to 785 CE.

Throughout history, several prominent individuals have borne the name Mehdi, including Mehdi Qoli Hedayat (1799-1845), an Iranian philosopher and writer, and Mehdi Bazargan (1907-1995), an Iranian scholar, academic, and the first Prime Minister of Iran after the Iranian Revolution in 1979.

Another notable figure was Mehdi Huseyn Hayat Tabrizi (1853-1920), an Azerbaijani educator, philosopher, and playwright, who played a significant role in the cultural and literary renaissance of Azerbaijan in the late 19th and early 20th centuries.

In the realm of sports, Mehdi Ben Attia (born 1967) is a Tunisian former football player and coach, while Mehdi Bagheri (born 1976) is an Iranian former football player and current manager.

The name Mehdi has also been borne by several religious leaders and scholars throughout Islamic history, such as Mehdi Ebrahimi Vafa (1925-2022), an Iranian Shia cleric and philosopher, and Mehdi Hairi Yazdi (1923-1999), an Iranian Shia cleric and scholar.