Originally an offshoot of the Final Fantasy franchise, the Mana series has since taken on a life of its own. The world of Mana is governed by the Mana Tree, a great, ancient, and all-powerful plant that's constantly under threat by all manner of evil creatures. It is up to the Gemma Knights, the protectors of Mana, to defend their leafy charge - and the world at large.

The Mana series has kind of a non-specific, sticky timeline at times, so this chronology is up for debate. That said, Dawn of Mana is almost certainly first, and Secret of Mana is almost certainly last. 

A few of the titles are seemingly not canonical to the main series, and thus appear only under Release Order.

In-Universe Chronological Order Release Order