The language known as Mon Calamari was used by the sentient species of the same name. These beings were native to the planet Mon Cala. Humans also possessed the ability to speak it. Around 230 BBY, Ghal Tarpfen, who held the position of Mon Calamari Head of Security at the Galactic Republic's space station called Starlight Beacon, had not encountered her native tongue since leaving her homeworld many years prior. However, after learning that she was the target of a blackmail scheme orchestrated by the Nihil pirates, Tarpfen was surprised by an ambush from the traitorous Republic Senator Ghirra Starros. Starros addressed Tarpfen in broken Mon Calamari, stating that Tarpfen should have obeyed instructions, before one of Starros' associates rendered Tarpfen unconscious.
The Mon Calamari language made its first canonically appearance within the Star Wars Insider short story titled "Starlight: Shadows Remain" by Justina Ireland. The initial segment of this story was released in issue 207 on December 14, 2021. Within the Star Wars Legends continuity, Mon Calamarian received its initial mention in The Star Wars Sourcebook, a 1987 sourcebook by West End Games. Its first appearance occurred in the 1994 novel Dark Apprentice, penned by Kevin J. Anderson.
A writing system bearing a similar name, Calamarian, was introduced in "Rose Knows," a comic featured in the sixth issue of the 2017 Star Wars Adventures series. As of yet, no connection has been established linking the language and the writing system.