The Secret World of Alex Mack is an American science fiction television series that aired on Nickelodeon from October 8, 1994, to January 15, 1998.

Alexandra "Alex" Mack is an ordinary teenage girl living with her parents, George and Barbara, and her precocious older sister, Annie, in the industrial town of Paradise Valley, Arizona.

While walking home after her first day of junior high school, Alex is nearly hit by a truck from Paradise Valley Chemical, and during the incident, she is accidentally drenched with GC-161, an experimental substance developed by the factory.

Alex finds this exciting and fun; however, her powers prove to be unpredictable (occasionally, her skin glows a bright yellow when she is nervous).

She confides only in Annie and her best friend Ray, choosing to keep her powers a secret from everyone else, including her parents, for fear of what the chemical factory's CEO, Danielle Atron, will do to her if she finds out.

Thomas W. Lynch, who had created the programs Night Tracks and Kids Incorporated, said the idea for the series was based on an incident from his own childhood.

[7] Lynch's father, a nuclear physicist, worked with radioactive material in the family's garage and the chemical spilled out of its container.

Internationally, it also aired on YTV in Canada, Kabel 1 in Germany, SVT in Sweden, France 2 in France, Viasat 3 in Hungary, Rai 1 in Italy, Fox Kids in Latin America, Channel 4 in the UK, NHK in Japan and was in the children's weekday lineup for much of the mid-to-late 1990s on the ABC in Australia.

The Secret World of Alex Mack 20 Year Reunion was recorded in 2018 and released as a TV movie on YouTube and Vimeo.

Alexis Fields (Nicole) had gone on to a career in interior design, John Marzilli (Vince) had adopted a son who attended the cast reunion, and Darris Love (Ray) became involved in acting and music.

A single VHS volume containing two episodes titled "In the Nick of Time" was released by Sony Wonder in the United States in 1996.

[11] The set is noteworthy for giving Jessica Alba top billing on the package, most likely in an effort to sell more copies, even though she actually only appears in a supporting role, and only in a few episodes.

[13] It was eventually revealed by the BBFC that the '15' rating was applied to the boxed set because of a season 1 episode called "Shock Value" where Alex is seen climbing into a clothesdryer from the pilot.

According to the BBFC, "The presentation of this behaviour is comic and no negative consequences are shown which would warn young viewers of the potential dangers of hiding in such appliances.