Writer – The Maxx, Wonder Woman, Flash
Illustrator – Journey, Grim Jack

William’s first comics work was for Power Comics Company and on Noble Comics’ Justice Machine with Mike Gustovich. His first ongoing series was Journey: The Adventures of Wolverine MacAlistaire, about 19th-century Michigan frontier life, which he both wrote and illustrated. He wrote the 31-issue Jonny Quest series published by Comico from 1986 to 1988 and collaborated with artist Adam Kubert on the Jezebel Jade limited series, a spin-off from the Jonny Quest series.[7]

In 1988, he began writing The Flash with issue #15 and continued through #61. He and artist Greg LaRocque introduced Linda Park as a supporting character in the series in The Flash vol. 2 #28 (July 1989). He also reintroduced the Pied Piper as a reformed villain and established the character as gay, in issue #53 (Aug. 1991).

Meanwhile he wrote Dr. Fate #25-41 and the Jaguar series for DC’s Impact Comics imprint. He wrote Epicurus the Sage which was illustrated by Sam Kieth, and scripted The Maxx which was illustrated and co-written by Kieth. In 1990, Messner-Loebs became the writer of the Batman newspaper comic strip and wrote the strip until its cancellation the following year.

In 1992 Loebs took over writing the Wonder Woman series, with pencils by Mike Deodato. During his run from #63 to #100, he created the character Artemis of Bana-Mighdall, for whom he wrote the mini-series Artemis: Requiem. Meanwhile he wrote Hawkman #9-27, penciled primarily by Steve Lieber.[12] In 1996 he had a brief run writing Marvel Comics’ Thor. From 1997 to 1999 he wrote Impulse #29-49, penciled by Craig Rousseau. In 1999 he wrote the “V2K” mini-series Brave Old World for Vertigo, penciled by Guy Davis.

His financial situation, following years of limited freelance work and the loss of his and his wife’s home in the early 2000s, was publicized in the local newspaper and comics news sites and message boards on the Internet. Author Clifford Meth teamed up with artist Neal Adams to create a benefit auction to help Messner-Loebs. The two also created an art tribute book entitled Heroes & Villains with all proceeds aiding Messner-Loebs.

His financial situation improved somewhat, and he had a number of works published, including an issue of Green Arrow in 2006, and several pieces in The Three Tenors (Aardwolf Publishing), which he shared credits for along with Clifford Meth and artist Dave Cockrum. A new “Journey” story was included in the one-shot Many Happy Returns in 2008, and IDW Publishing reprinted the original material in paperback. He has done writing for Boom! Studios, including the four-issue Necronomicon and a story for Zombie Tales. He has done illustration work for the 2007 humor book Chicken Wings for the Beer Drinker’s Soul and a monthly cartoon for the Livingston [County, MI] Parent Journal. In 2008, he discussed additional, more substantial new works with various publishers. In 2011, he wrote the DC Retroactive: The Flash – The ’80s and DC Retroactive: Wonder Woman – The ’90s one-shots.

As of early 2018, William Messner-Loebs and his wife have continued to struggle financially, with Messner-Loebs working two part-time positions in Michigan.