Sigrid Nansen is a superhero in American comic books published by DC Comics, first appearing in Super Friends #9 (December 1977). Originally known as Icemaiden, they replaced the hero known as Ice for a time. They are one of multiple ice-themed characters in the DC Universe. The character was re-introduced during "Infinite Frontier" in which they adopt the new identity of Glacier and identify as non-binary.

Sigrid Nansen received her powers as the result of an experiment funded by the Norwegian government. In an attempt to please both her overbearing scientist mother (who constantly belittled her for not having a boyfriend and not being a top scientist) and the Norwegian government, Sigrid reluctantly agreed to the experiments. The goal was to duplicate the abilities of what at the time were a legendary tribe of ice-people; the experiment was a success, though as a side-effect, Sigrid's skin permanently turned blue. Taking the name Icemaiden, she joined the Global Guardians as her country's representative to that international super-team.

During the DC miniseries Legends, the people of the United States were turned against all heroes, superheroes, and metahumans; the President decreed that no costumed hero could operate legally. This did not affect the Global Guardians, however, who worked outside of the U.S. During this time, what Sylvester Pemberton referred to as the "Great Super-Hero Scare" Doctor Mist sent Icemaiden, along with Rising Sun, Tasmanian Devil, and Green Flame to Canada to run security for the international Trade Conference. Icemaiden fell victim to Injustice Unlimited and was hypnotized into serving the villains. This resulted in her traveling to Greenland with Jade and the new Icicle on a mission to find and free Solomon Grundy. In the end, the villains were defeated and Icemaiden regained her free will.

Upon the discovery of a real tribe of ice-people, their princess Tora Olafsdotter (Ice) joined the Global Guardians. This led Sigrid to quit the team.

Years later, after Ice had left the Global Guardians, joined the Justice League International, and was killed by the Overmaster, Sigrid re-emerged. She chose to honor the fallen heroine by serving as her replacement in the Justice League.

There were hints of a romantic relationship with her teammate Fire, but this was all part of a plan hatched by Sigrid. Realizing Fire was not coping with Ice's death (and Fire was attempting to control her, much like Sigrid's mother had done growing up), they dressed up to resemble Ice and showed romantic feelings toward Fire. The shock made Fire realize that Ice was gone, and she could not recreate the past. During her time in the JLA, she was disliked and criticized by Guy Gardner, who had also not come to terms with Ice's death.

She left active duty with the League after they and several others were heavily wounded during the attack of the Hyperclan (White Martians). Later recovered, Sigrid resumed her superhero career and is assumed to have eventually joined an unofficial branch of Justice League Europe. That League chapter was, however, infiltrated by Mist, who apparently lured Icemaiden away and subsequently disguised herself as the blue-skinned hero before killing three League members: Crimson Fox, Amazing Man, and Blue Devil.

In the same story, it was revealed that Mist covertly contacted Icemaiden and informed her of a supposed threat facing her homeland of Norway, and she must defeat the threat without informing anyone until afterwards. Icemaiden left during the middle of the night, and Mist replaced her within the JLE by the next morning. The JLE did not know that Mist replaced Icemaiden until Mist began her attacks against them. Mist informed Crimson Fox that the threat she informed Icemaiden about was not real, and that she had sent Icemaiden on an ultimately fruitless search so that she could disguise herself as Icemaiden and replace them on the team.