- Even though he says he only did it once, Sean was teased on the Firefly set for calling his onstage sister by her real name, Summer, rather than her character name, River.
- During the Meet & Greet at the Serenity Cubed convention in Heathrow/UK, September 2006, Sean revealed to some participants that he used to have several piercings: One in his tongue, one in his bellybutton, and five in his left ear. He would take out the tongue stud (and the rest of them, we assume) for filming and public events, since it made him talk funny. (Source: kneonlight)
- Also at the above Meet & Greet, Sean mentioned to some other participants that he is learning French. (Source: greenie_breizh)
- A picture of Sean was featured in WikiHow: How to Apply Makeup as a Man
- Sean introduced Eyal Podell, who attended Byram Hills High School with him in Armonk, New York, to his future wife. (Source: Ynetnews)
- According to his Firefly/Serenity co-star Jewel Staite, Sean is a good kisser and "smells yummy", but shooting the kissing scene for Serenity was hard because they had developed a brother/sister relationship, so they were constantly giggling nervously and being silly. (Source: SGP-
- Wedding Wars co-star John Stamos, whose boyfriend Sean played, concurs with Jewel's assessment of Sean's kissing abilities. (Source: Gay.com)
- About 20 minutes into his "Radio Free Burrito Episode Zero" podcast from December 1, 2005, Wil Wheaton tells the story of how he met Sean at an audition and turned into a "drooling fanboy". Very much worth downloading. :) (Source: WWdN: In Exile)
- In an interview for the Lifetime TV website, Michelle Trachtenberg told the following story from the shoot of The Dive from Clausen's Pier: In one scene with Sean Maher, who plays Kilroy, he and I are eating a Christmas dinner and weren't aware how onion-ridden the green bean casserole was. We had a make-out scene right afterward and because Sean didn't have to eat as much as I did, I forced him to take a few bites between takes. If I had to have crusty onion breath when we kissed, he was going to have the same heinous breath as well! (Source: Lifetime TV)
- While he was at NYU, Sean waited tables (Source: unknown)
- He's a big fan of Purell (Source: an unknown report from the Living 'til the End premiere)
- Sean is a yoga enthusiast (Source: unknown article)
- Sean's first convention experience was the San Diego Comic-Con in 2004.