Which script is used for the Shahada on Saudi Arabia's flag?

The Shahada on Saudi Arabia’s flag is written in the Thuluth script.

Thuluth is a formal Arabic calligraphic style known for its sweeping curves, elongated vertical strokes, and carefully balanced composition. On the flag, it renders the Islamic declaration of faith: “There is no god but God; Muhammad is the Messenger of God.” The inscription appears above a white sword on a green field.

The Shahada has appeared on Saudi-associated banners since the eighteenth century, when the Al Saud became linked with the religious movement of Muhammad ibn Abd al-Wahhab. Abdulaziz ibn Saud added a sword in 1921. The design was broadly settled by 1938, but official standardization came on 15 March 1973.

A common mix-up is confusing the script with Kufic, another famous Arabic style often associated with religious inscriptions. Another easily missed detail is that the Saudi flag is made with identical obverse and reverse sides, so the sacred text reads correctly from both directions. The sword points left on both sides.