Square script may refer to any of several scripts with blocky letters used to write various languages:

Arabic

Square Kufic

Aramaic

Aramaic square script, a form of Imperial Aramaic that emerged as a writing system for the Aramaic language in the 5th century BC

Hebrew

Ktav Ashuri, "Assyrian script" or "Jewish square script", identical to Aramaic square script but adopted by Jews to write Biblical Hebrew the modern Hebrew alphabet (as opposed to the old Paleo-Hebrew and the later Samaritan script)

Latin characters

square hand, a variant of nyctography that doesn't require the reader to know a cipher; sometimes used by DeafBlind people to communicate with sighted people

Mongolian

'Phags-pa script Zanabazar square script