Linear A is one of two currently undeciphered writing systems used in ancient Greece (Cretan hieroglyphic is the other). Linear A was the primary script used in palace and religious writings of the Minoan civilization. It was discovered by archaeologist Sir Arthur Evans. It is the origin of the Linear B script, which was later used by the Mycenaean civilization.

In the 1950s, Linear B was largely deciphered and found to encode an early form of Greek. Although the two systems share many symbols, this did not lead to a subsequent decipherment of Linear A. Using the values associated with Linear B in Linear A mainly produces unintelligible words. If it uses the same or similar syllabic values as Linear B, then its underlying language appears unrelated to any known language. This has been dubbed the Minoan language.

Linear A has hundreds of signs. They are believed to represent syllabic, ideographic, and semantic values in a manner similar to Linear B. While many of those assumed to be syllabic signs are similar to ones in Linear B, approximately 80% of Linear A's logograms are unique; the difference in sound values between Linear A and Linear B signs ranges from 9% to 13%. It primarily appears in the left-to-right direction, but occasionally appears as a right-to-left or boustrophedon script.

An interesting feature is that of how numbers are recorded in the script. The highest number that has been recorded is 3000, but there are special symbols to indicate fractions and weights.

Linear A has been unearthed chiefly on Crete, but also at other sites in Greece, as well as Turkey and Israel. The extant corpus, comprising some 1427 specimens totalling 7362–7396 signs, if scaled to standard type, would fit on a single sheet of paper.