Nicole Randall Johnson was born in Los Angeles, California, but her childhood was marked by frequent moves, as she was also raised in Portland, Oregon, and Phoenix, Arizona. This peripatetic upbringing likely instilled in her a sense of adaptability and resilience, qualities that would serve her well in her future endeavors.
Johnson's formal education took place at the University of Arizona in Tucson, where she earned a Bachelor of Fine Arts degree in Acting and Directing. After completing her degree, she relocated to Los Angeles, where she embarked on a three-year training program in sketch and improvisation at the prestigious Groundlings School and Theatre.
As a performer and writer for the Groundlings Sunday Company, Johnson honed her skills and gained valuable experience. Her talents did not go unnoticed, and she soon landed a role as a series regular on the NBC/Bravo comedy series Significant Others in 2004. This exposure paved the way for her subsequent appointment as a series regular and writer on the FOX Television show Mad TV, where she appeared during its 11th and 12th seasons.
Johnson's impressive tenure on Mad TV saw her create a range of memorable characters, including the popular recurring roles of "Ka-son" and "Da-rell." These characters were the focus of several sketches that have garnered an astonishing 35 million views on YouTube. Her celebrity impersonations on the show included notable figures such as Condoleezza Rice, Oprah Winfrey, Eddie Murphy, Queen Latifah, Chris Rock, Beyoncé, Randy Jackson, Tyra Banks, Chandra Wilson, Star Jones, Mo'Nique, and Isabel Sanford.
In addition to her television work, Johnson has also appeared in a number of films, working with acclaimed directors such as Todd Phillips, Judd Apatow, Michael Bay, Curtis Hanson, Ken Kwapis, and Bob Odenkirk. Her feature film debut came in 2008, when she starred opposite Paul Rudd and Seann William Scott in the David Wain-directed comedy Role Models, released by Universal Pictures.