FIAT (FInite element Automatic Tabulator) is a Python package for computing general families of finite elements.

Fiat currency, money issued by government fiat

"Let there be" in Latin, as in

Fiat Lux, let there be light (Genesis)

Military fiat, process where a decision is made and enforced by military means without participation of political elements

Fiat (magical formula), a magical formula.

Fiat (policy debate), a theoretical construct in policy debate

Fiat is an Italian automobile manufacturer. Fiat may also mean:

The Fiat Tagliero Building in Asmara, Eritrea.

Mary's "Fiat", the Virgin Mary's response to the Annunciation ("Let it be to me according to thy word")