So, there seems to have been a trend in the 80's, 90s and early 2000's of Trek cast members trying their hand at writing their own scifi (or other things), probably inspired by William Shatner's success. I've compiled a list of what I could find, so here I present them. It does not include autobiographical works because that's covered in another thread. I honestly wasn't sure all of what Wil Wheaton's books were Trek related or autobiographical. What else have I missed? Fiction: Burton, Levar - Aftermath Collins, Stephen - Eye Contact Collins, Stephen - Double Exposure: A Novel Tenebra trilogy: Dawson, Roxann & Graham, Daniel - Entering Tenebrea Dawson, Roxann & Graham, Daniel - Tenebrea's Hope Dawson, Roxann & Graham, Daniel - Tenebrea Risingde Lancie, John & Cool, Tom - Soldier of Light The Flight Engineer series: Doohan, James & Stirling, S. M. - The Rising Doohan, James & Stirling, S. M. - Privateer Doohan, James & Stirling, S. M. - The Independent CommandDorn, Michael & Hemingway, Hilary - Time Blender Eisenberg, Aaron - Short story in The Best of Tales: Volume One Frakes, Jonathan & Smith, Dean Wesley - The Abductors Conspiracy Koenig, Walter - Buck Alice & the Actor-Robot Saturna series: Nichols, Nichelle & Bonanno, Margaret Wander - Saturn's Child Nichols, Nichelle & Meechan, Jim - Saturna’s QuestRobinson, Andrew J. - Lexa and the Gordian Maze of Terra Robinson, Andrew J. - Lexa and the Smugglers of Cyclo Robinson, Andrew J. - Lucas Knight and the Reaper of Chaos Quest for Tomorrow series: Shatner, William - Delta Search Shatner, William - In Alien Hands Shatner, William - Step into Chaos Shatner, William - Beyond the StarsWar series: Shatner, William - Man O' War Shatner, William - The Law of WarTekWar series: Shatner, William & Goulart, Ron - TekWar Shatner, William & Goulart, Ron - TekLords Shatner, William & Goulart, Ron - TekLab Shatner, William & Goulart, Ron - Tek Vengeance Shatner, William & Goulart, Ron - Tek Secret Shatner, William & Goulart, Ron - Tek Power Shatner, William & Goulart, Ron - Tek Money Shatner, William & Goulart, Ron - Tek Kill Shatner, William & Goulart, Ron - Tek NetSamuel Lord series: Shatner, William & Rovin, Jeff - Zero-G Shatner, William & Rovin, Jeff - Zero-G: Green SpaceShatner, William & Tobias, Michael - Believe: A Novel Shawn, Wallace - Essays Shawn, Wallace - Night Thoughts The Merchant Prince Trilogy: Shimerman, Armin & Scott, Michael - The Merchant Prince Shimerman, Armin & Yarbro, Chelsea Quinn - Outrageous Fortune Shimerman, Armin - Capital OffenseTakei, George & Asprin, Robert - Mirror Friend, Mirror Foe Wheaton, Wil - The Happiest Days of Our Lives Wheaton, WIl - Dancing Barefoot Wheaton, Wil - Clash of the Geeks Wheaton, Wil - "Laina" (short story) from From a Certain Point of View Comics: Koenig, Walter - Walter Koenig's Raver Koenig, Walter - Walter Koenig's Things to Come Nimoy, Leonard - Leonard Nimoy's Primortals Shatner, William - William Shatner's Man O' War Shatner, William - William Shatner Presents Tek War Chronicles Shatner, William - Quest for Tomorrow Plays: Phillips, Ethan - Penguin Blues: A One-Act Play Shawn, Wallace - Four Meals in May Shawn, Wallace - The Family Play Shawn, Wallace - The Hotel Play Shawn, Wallace - The Hospital Play Shawn, Wallace - Our Late Night Shawn, Wallace - A Thought in Three Parts Shawn, Wallace - Marie and Bruce Shawn, Wallace - Aunt Dan and Lemon Shawn, Wallace - The Fever Shawn, Wallace - The Designated Mourner Shawn, Wallace - The Threepenny Opera Shawn, Wallace - Grasses of a Thousand Colors Shawn, Wallace - Evening at the Talk House Poetry: Nimoy, Leonard - You & I Nimoy, Leonard - Will I Think of You? Nimoy, Leonard - We Are All Children Searching for Love: A Collection of Poems and Photographs Nimoy, Leonard - Come be With Me Nimoy, Leonard - These Words are for You Nimoy, Leonard - Warmed by Love Nimoy, Leonard - A Lifetime of Love: Poems on the Passages of Life
Wil Weaton wrote a short story for the Star Wars Anniversary collection "From a Certain Point of View" https://starwars.fandom.com/wiki/Laina_(short_story)
I read Armmin Shimmerman's Doctor Dee novel I got from the library that takes place in Elizabethan England it was a really good fantasy story. I really enjoyed reading it.I also read William Shatner's Techwar series from the library.
Walter Koenig wrote the SF novel "Buck Alice and the Actor Robot". Stephen Collins wrote "Eye Contact" and "Double Exposure: A Novel".
I dunno if they count as non-Trek (never having read them, they may or may not have to do with Star Trek), but Deforest Kelley wrote a couple of poems. https://www.amazon.com/Big-Birds-Dream-DeForest-Kelley/dp/B0007C68WA/ https://www.amazon.com/Dream-Goes-Original-DeForest-Kelley/dp/B008ZFKZD4/