Kia Stevens, who plays Tamee/Welfare Queen in the series, is the only female cast member who is actually a professional wrestler. Stevens has been a champion all over the world wrestling under the name Awesome Kong (sometimes Amazing Kong). She also briefly wrestled in WWE as Kharma.
The wrestler who trained the actresses for this series, Sal Guerrero aka Chavo Guerrero, Jr. is the nephew of Armando Guerrero aka Mando, the trainer for the wrestlers on the original series on which this one is based.
Ursula Hayden is the owner of GLOW - Gorgeous Ladies of Wrestling. She was on the original GLOW in the 1980s as Babe, the Farmer's Daughter and she bought the company in 2001. She is also a story consultant on GLOW Netflix.
In Spain, a promotion campaign for the series involved singers Marta Sánchez and Vicky Larraz rekindling their rivalry over their respective stints in band Olé Olé, fitting with the show being set in the '80s. The final video of said campaign featured Sánchez and Larraz stepping into the ring.
Marc Maron, who plays manager Sam Sylvia, is a well-known comedian with several stand-up specials, a filmmaker himself, and is perhaps best-known for his acclaimed podcast ("WTF with Marc Maron"), which was ranked as the #1 podcast on iTunes for several years running.
When the girls go to the wrestling event, professional wrestlers Christopher Daniels and Frankie Kazarian make an appearance wrestling each other. They are currently signed with Ring of Honor (ROH) as a tag-team called The Addiction. Also interesting to note, the building they are wrestling in is the American Legion Post #308 in Reseda, CA which is the same building that Pro Wrestling Guerrila (PWG) holds events in.
The trivia item below may give away important plot points.
There are several references to the mythical Greek king Oedipus and the Oedipus complex in Sam Sylvia's films. In the myth, Oedipus killed his father and married his mother whilst unaware of their true identity. When Sylvia finds out that the plot for his screenplay Mothers & Lovers is similar to the newly released Back to the Future (mother attempts to seduce time travelling son whilst unaware of his true identity), he becomes upset and is next seen lying on the floor of a hotel room. Sylvia is visited by Justine who attempts to comfort him. He attempts to come on to her but she announces that she is his daughter. This mirrors the story of Oedipus, Mothers & Lovers, and Back to the Future.