Michael O. Varhola (born September 24, 1966) is an author, publisher, and lecturer. He has written numerous books, games, and articles, and founded game development company and manufacturer Skirmisher Publishing LLC. He also served as the assistant editor of The Hilltop Reporter, a weekly newspaper located in Texas Hill Country. In 1997, he married Diane Varhola. In 2003, he changed his middle name from James to Odysseus, but did not start using it publicly until 2011.

Varhola is a 1993 graduate of University of Maryland, College Park, from which he received a B.S. in journalism. Other schools he attended include the Metropolitan State University of Denver, Colorado, and the American University of Paris. He graduated from high school at Carson Long Military Institute in New Bloomfield, Pennsylvania.

Varhola has authored or co-authored the non-fiction books Everyday Life During the Civil War (1999), Fire and Ice: The Korean War, 1950-1953 (2000), D-Day: The Invasion of Normandy, June 6, 1944 (2001), Shipwrecks and Lost Treasure of the Great Lakes (2007), Ghosthunting Virginia (2008), Ghosthunting Maryland (2009), Life in Civil War America (2011), Texas Confidential: Sex, Scandal, Murder, and Mayhem in the Lone Star State (2011). He also wrote the fiction title Swords of Kos: Necropolis (2012).

Varhola is the co-author of several gaming books, including Experts (2002), Warriors (2003), Tests of Skill (2004), Nuisances (2005), Experts v.3.5 (2005), Nation Builder (2005), Gary Gygax's Gygaxian Fantasy Worlds Volume 6: Nation Builder (2006), H.G. Wells' Little Orc Wars (2007), Nuisances: Director's Cut (2007), and City Builder: A Guide to Designing Communities (2011).

Varhola published and wrote introductions to editions of H.G. Wells' Little Wars (2004) and Floor Games (2006) and Robert Louis Stevenson's Stevenson at Play.