Timothy Zahn was born in Chicago, Illinois. He attended Michigan State University, earning a Bachelor of Science degree in physics in 1973. He then moved to the University of Illinois at Urbana-Champaign and achieved an M.S. degree in physics in 1975. While he was pursuing a doctorate in physics, his thesis adviser quite suddenly died, leaving Zahn with three years of thesis work down the drain. Zahn never completed the doctorate. In 1975 he had begun writing science fiction as a hobby, and later he became a professional writer. He and his wife Anna live in Bandon, Oregon. They have a son, Corwin Zahn.

Zahn's characters are noteworthy for taking various pieces of information, putting together a picture of events, and planning a course of action around it. Grand Admiral Thrawn is a character that reflects this. Zahn's Star Wars books also usually focus on a certain core group. Throughout these books, he often makes references to other characters or events that were created by him in previous works. As with the original Star Wars trilogy, all books in both The Thrawn Trilogy and The Hand of Thrawn Duology begin with an "exterior shot" of a Star Destroyer. Zahn tends to focus more on the logic of his characters (as with Thrawn) rather than their feelings and has characters from the original trilogy re-use some of their distinctive dialogue. Timothy Zahn is also acredited with naming the galactic hub of the Star Wars universe, Coruscant.

Zahn's books are often described as "fast-paced". For example, he tends to develop settings only as necessary to advance the plot.

A distinguishing mark of his work is his fondness for obliquely referential wordplay. For instance, in the Thrawn trilogy, the name "Thrawn" comes from a word meaning "twisted", while the names of two pets..."Sturm" and "Drang"...are actually the real-world German words for "Storm" and "Urge", and seem to nod directly toward the "Sturm und Drang" writing style born out of the German Romantic movement. Given that the Star Wars science-fantasy saga is overtly rooted in Romanticism, Zahn's arcane referencing here would seem appropriate.

The names of characters, planets, and solar systems seem to betray a certain acquaintance with both ancient Norse and Semitic (Hebrew, Arabic) lexic and morphology. Note, for instance, the mysterious planet Myrkr with its near-impenetrable forests and utter "darkness" in the Force (cf. Old Norse myrkr "darkness"), or the literally-minded species Elomin, sg. Elom (cf. the Hebrew m.pl. suffix -im). There are numerous instances of both medieval literature/saga and Old Testament references in his Star Wars novels. However, it is uncertain whether the linguistic patterns (associated with these sources) are intentional or simply a side-effect of said familiarity.

Blackcollar Series

• The Blackcollar (1983)
• The Backlash Mission (1986)
• The Judas Solution (2006)

Both The Blackcollar and The Backlash Mission were released in one joint novel titled Blackcollar in 2006.

Cobra Series

• Cobra (1985)
• Cobra Strike (1986)
• Cobra Bargain (1988)

The first two books were also released in one compilation called Cobras Two in 1992. A complete compilation was released as the Cobra Trilogy in 2004.

Cobra War Series

• Cobra Alliance (2009)
• Cobra Guardian (forthcoming)

Conquerors Trilogy

• Conquerors' Pride (1994)
• Conquerors' Heritage (1995)
• Conquerors' Legacy (1996)

Star Wars

Thrawn trilogy

• Heir to the Empire (1991)
• Dark Force Rising (1992)
• The Last Command (1993)

Hand of Thrawn series

• Specter of the Past (1997)
• Vision of the Future (1998)

Other Star Wars novels

• Survivor's Quest (2004)
• Outbound Flight (2006)
• Allegiance (2007)

Graphic novels

• By the Emperor's Hand; a graphic novel with Michael A. Stackpole (1999)
• A Night on the Town, comic in Star Wars Tales 1
• Specter of Thrawn (cancelled)

Shorter works

• The Dreamsender short story (1980)
• Dark Thoughts at Noon short story (1982)
• Pawn's Gambit short story and Hugo nominee (1982)
• When Jonny Comes Marching Home short story (1982)
• Cascade Point short story and Hugo winner (1983)
• The Final Report on the Lifeline Experiment short story (1983)
• Return to the Fold short story and Hugo nominee (1984)
• Teamwork short story (1984)
• Music Hath Charms short story (1985)
• Spinneret short story (part 1 of 4) (1985)
• Spinneret short story (part 2 of 4) (1985)
• Spinneret short story (part 3 of 4) (1985)
• First Contact: short story in Star Wars Adventure Journal 1, later republished in Tales From the Empire (1994)
• The Saga Begins: short story in The DarkStryder Campaign (1995)
• Mist Encounter : short story in Star Wars Adventure Journal 7, later republished in the paperback edition of Outbound Flight (1995)
• Hammertong: short story in Tales from the Mos Eisley Cantina (1995)
• Sleight of Hand: short story in Tales from Jabba's Palace (1996)
• Command Decision: short story in Star Wars Adventure Journal 9 (1996)
• Side Trip: novella with Michael A. Stackpole in Star Wars Adventure Journal 12 and Star Wars Adventure Journal 13, later republished in in Tales From the Empire (1997)
• Jade Solitaire: short story intended for the cancelled Star Wars Adventure Journal 17, later published in Tales from the New Republic (1999)
• Interlude at Darkknell: novella with Michael A. Stackpole, in Tales from the New Republic (1999)
• With One Stone: Honorverse short story in The Service of the Sword (2003)
• Fool's Bargain: eBook; also reprinted in the paperback edition of Survivor's Quest (2004)
• Hero of Cartao: short story in Star Wars Insider
• Changing Seasons: short story in Star Wars Insider
• Judge's Call: short story on Del Rey's website.
• Duel: short story / Hasbro tie-in.
• Handoff: short story in Star Wars Gamer
• Sword's Man: short story in Space Gamer
• Symmkyn's Edge: short story in Space Gamer
• Vampire Trap: short story in Space Gamer
• Fantasy World: short story in Space Gamer
• The Challenge: short story in Space Gamer

Dragonback series

• Dragon and Thief (2003)
• Dragon and Soldier (2004)
• Dragon and Slave (2005)
• Dragon and Herdsman (2006)
• Dragon and Judge (2007)
• Dragon and Liberator (2008)

Quadrail or Frank Compton series

• Night Train to Rigel (2005)
• The Third Lynx (2007)
• Odd Girl Out (2008)
• The Domino Pattern (2009)

Other novels

• Spinneret (1985)
• A Coming of Age (1985)
• Triplet (1987)
• Deadman Switch (1988)
• War Horse (1990)
• The Icarus Hunt (1999)
• Angelmass (2001)
• Manta's Gift (2002)
• The Green and the Gray (2004)
• From the Ashes (2009)
• Trial by Fire (2010)

Collections

• Cascade Point and Other Stories (1986)
• Time Bomb and Zahndry Others (1988)
• Distant Friends and Other Stories (1992)
• Star Song and Other Stories (2002)