Thaana, Tãna, Taana or Tāna ( ތާނަ ) is the present writing system of the Maldivian language spoken in the Maldives.

H. C. P. Bell, the first serious researcher of Maldivian documents,[citation needed] used the spelling Tāna, as the initial consonant is unaspirated.

The spelling Thaana was adopted in the mid-1970s, when the government of the Maldives embarked on a short period of Romanization; /t/ was transcribed ⟨th⟩, as ⟨t⟩ was used for the voiceless retroflex plosive [ʈ].

The oldest written sample of the Thaana script is found in the island of Kanditheemu in Northern Miladhunmadulu Atoll.

It is inscribed on the door posts of the main Hukuru Miskiy (Friday mosque) of the island and dates back to 1008 AH (AD 1599) and 1020 AH (AD 1611) when the roof of the building was built and then renewed during the reigns of Ibrahim Kalaafaan (Sultan Ibrahim III) and Hussain Faamuladeyri Kilege (Sultan Hussain II) respectively.

The remaining letters for loanwords (z ṭ y p j c ñ) and Arabic transliteration (h̤ ḵ ž ʕ ġ w ẕ t̤ ẓ s̱ q s̤ ż ś) are derived from phonetically similar native consonants by means of diacritics (like nuqta), with the exception of yaa, which is of unknown origin.

(The Ogham script used in 1st millennium AD Ireland is another example, which also has some relation to numbers, since most of its letters are differentiated from others in a way similar to tally marks.)

Maldivian learned men, who were all well versed in sorcery, saw the advantages of writing in this simplified hidden script, and Thaana was gradually adopted for everyday use.

Towards the mid-1970s, during President Ibrahim Nasir's reign, Telex machines were introduced by the Maldivian government in the local administration.

The Thaana script was reinstated by President Maumoon Abdul Gayoom shortly after he took power in 1978, although the Latin transcription of 1976 continues to be widely used.