Antonelli is a professional journalist. In January 2015, he was named managing editor of The Clarksville Times based in Clarksville, Texas. Antonelli got a late start in his fiction writing career; his first story was published when he was 46 years old. His first professional sale was "A Rocket for the Republic", published in Asimov's Science Fiction in September 2005. His 2012 short story "Great White Ship" was nominated for the Sidewise Award for Alternate History. he had 112 short stories published either in print or online. His stories have appeared in Asimov's Science Fiction, Worlds of Wonder, Jim Baen's Universe, Continuum Science Fiction, Astounding Tales, Bewildering Stories, Andromeda Spaceways In-flight Magazine, Nova Science Fiction, Planetary Stories, Aphelion, Ray Gun Revival, 4 Star Stories, Drink Tank, Nova Science Fiction, Omni Reboot, the Song Stories anthology, the FenCon IV Souvenir Program Book, and other publications. Eleven of his stories have received honorable mentions in The Year's Best Science Fiction published by St. Martin's Press for 2011, 2009, 2008, 2006, 2005 and 2004. "A Rocket for the Republic" placed third in the Asimov's Science Fiction Readers Poll for 2005 in the Short Story category. His 2012 short story "Great White Ship" was nominated for the Sidewise Award for Alternate History. "On a Spiritual Plain" was nominated for Hugo Award for Best Short Story in 2015. His debut novel, "Another Girl, Another Planet", was nominated for the Dragon Award for Best Alternate History novel in 2017. He was an Active Member of the Science Fiction and Fantasy Writers of America, but has since left the organization as of 2017.
In July 2015, in the midst of the "Sad Puppies/Rabid Puppies" controversy, Antonelli wrote a letter to the Spokane Police Department telling them to be on the lookout for World science fiction conventionGuest of HonorDavid Gerrold as a person who may incite violence calling him "insane and a public danger and needs to be watched when the convention’s going on." Antonelli later apologized, and Gerrold accepted the apology, saying "Let's put this one to bed, once and for all. Lou Antonelli did something dumb. People were outraged. Someone who cared about him held up a mirror and he recognized he was turning into his own crazy uncle. He apologized. I'm satisfied that his apology was sincere. And that should be the end of it."
Personal life
He is married to Patricia Antonelli, a Dallas native.