Nichols, who played Lt. Uhura on Star Trek in the 1960s, will join fellow Trekker George Takei as a Heroes regular when the second season of the series begins in America this autumn (07).
The actress will play a financially-strapped grandmother, who is forced to take care of her two granddaughters after the death of their mother - her daughter - in the 2005 storms.
One of her granddaughters is one of the show's new heroines Dana Davis.
Nichols announced her part in Heroes at a recent fan convention, and admits she was staggered by the response of devotees.
She tells TV Guide magazine, "The entire room went insane."
Source: WENN