The Southwest Script or Southwestern Script, also known as Tartessian, South Lusitanian and Conii script is a Paleohispanic script used to write an unknown language usually identified as Tartessian. Southwest inscriptions have been found mainly in the southwestern quadrant of the Iberian Peninsula, mostly in the south of Portugal, but also in Spain.

The Paleohispanic scripts are the writing systems created in the Iberian Peninsula before the Latin alphabet became the main script. Most of them are unusual in that they are semi-syllabic rather than purely alphabetic, despite having supposedly developed, in part, from the Phoenician alphabet.