Oliver Stark was asked to erase the two natural red marks close to his left eye. He refused, arguing that they were his trademark. In the flashback episodes when he was a child the red marks were added to his young counterpart.
In firefighting lingo, Alpha, Bravo, Charlie, Delta, are terms are used to designate the sides of a structure.
- "Alpha" refers to the front side of the structure
- "Bravo" refers to the left side of the structure,
- "Charlie" refers to the back side of the structure
- "Delta" refers to the right side of the structure
Oliver Stark was considering quitting acting and becoming a firefighter before getting cast as one on 9-1-1 (2018).
Jennifer Love Hewitt (Maddie Buckley Kendall) and Brian Hallisay (Doug Kendall) are married in real life with three kids. They also previously starred as husband and wife in the show The Client List - Clienti speciali' (2011).
In May 2023, the series was canceled by Fox and was renewed for a seventh season at ABC.