Born among a race of telepaths on the planet of Titan, one of Saturn's moons, Imra Ardeen was always a prodigy, even among her own people. Deciding to use her abilities for good, she applied for membership in the Science Police. However, on a passenger ship to Earth, she used her incredible powers to read the minds of a group of terrorists secretly on board who were planning to assassinate billionaire RJ Brande, who was also on their flight. She thwarted the attempt, along with two other teens -- Rokk Krinn of the planet Braal, and Garth Ranzz of the planet Winath. After saving Brande's life, the eccentric mogul asked the trio to form a Super-Hero team he would fund, and Imra became the Legion of Super-Heroes' Saturn Girl.
She would soon fall in love with fellow Legionnaire Lightning Lad, and the two would begin a very long courtship. When Lightning Lad died, Saturn Girl went to great lengths to bring her boyfriend back to life, creating an elaborate scheme in which she would sacrifice her own life to bring him back. Luckily, the creature called Proty died in her place, allowing Saturn Girl and Lightning Lad to pick up right where they left off. Eventually, after many adventures together with the Legion, Imra and Garth were married, and Legion bylaws were changed so that a married couple was allowed to remain on the team.
During a brief time in which the couple were on sabbatical from the Legion, Imra gave birth to twins, Graym and Garridan. But Garridan was kidnapped and taken back in time by the Lord of Apokolips Darkseid, where he was transformed into the deadly Legion villain Validus, member of the Fatal Five. He was later returned to normal when Imra begged Darkseid to return him to his true form. Imra came back as a full-time Legionnaire in 2987 when the villainous Universo enslaved the Earth, and it was Saturn Girl's mental powers which were key in liberating the planet. She became a full-time member of the Legion again, while her husband Lightning Lad stayed home on Winath as a full-time dad. Saturn Girl eventually retired again, and began running a plantation, which became very successful. She gave birth to twin girls, Dacey and Dorrit. During emergencies, she would continue to aid the Legion.
After the events of ZERO HOUR, a new version of a young Imra Ardeen was introduced. This version of the telepathic teen was actually a Science Police interrogator, and when she helped save RJ Brande under similar circumstances as in her previous incarnation, she was asked to join the Legion of Super-Heroes, which in this reality was a government-sponsored diplomatic peacekeeping force. Unlike before, this Imra was part of a love triangle with her fellow Legion co-founders, Cosmic Boy and Lightning Lad. This version of Saturn Girl and her Legion were later revealed to be part of the parallel Earth-247.
Another Saturn Girl appeared on yet another parallel Earth, Earth Prime. This version of Imra Ardeen was actually mute, as her race of Titanians were so advanced in their mental abilities they did not speak vocally. To talk to her teammates, she always used telepathic communication. Earth Prime's Imra has a hard time opening up to fellow members of the team, except for her beloved Lightning Lad.
After the events of INFINITE CRISIS, it was revealed that the original Legion still existed in the Multiverse. Imra was a member once more, and helped Superman when he traveled to the future to reunite with his childhood friends when the xenophobic Earth-Man threatened the planet. During the epic known as FINAL CRISIS: LEGION OF 3 WORLDS, it was Imra's telepathy which united three different Legions from across the Multiverse to join in battle against the monstrous villain the Time Trapper. She has appeared recently in the post-REBIRTH reality as a patient in Arkham Asylum in the 21st Century.