Girardi was born in Springfield, Virginia, a suburb of Washington, D.C., the youngest of four children (two sisters and one brother), and educated in Springfield, Athens, and Paris. "...I went to Catholic school, and she told us stories from the Bible. Then she left, and a Greek woman came and told us Greek myths. So as a narrative, it was the best education that you could get." His father was a CIA agent starting in Vienna, then Athens (during the military coup), and then Paris.

He co-created, wrote, and edited an underground newspaper in high school, titled The New Wave, then The Lee Wave, which included a comic strip titled "Gumshoe".

He majored in Studio Art at the University of Virginia, Charlottesville. He was first published during his undergraduate years in the Virginia Literary Review. After a brief stint at the Graduate Film School of the University of Southern California, he transferred to the University of Iowa where he graduated from the Writer's Workshop with an M.F.A. in Fiction Writing in 1986. He also received the James Mitchener Fellowship for the manuscript of an early novel.

Girardi labored for a decade, working at numerous odd jobs, writing seven unpublished novels, and several unproduced screenplays, before getting his first novel into print. Finally, an editor for Delacorte Press found the manuscript for Madeleine's Ghost on a friend's coffee table and fell in love with the story. "If I hadn't been published, I would have gone mad. I was getting very bitter. I don't know what I would have done. I would probably have joined the priesthood."

Girardi followed with Vaporetto 13, and The Pirate's Daughter. He collected some novellas and short stories with ethical and religious themes, entitled Seven Moral Tales. He also wrote the autobiographical piece for the Washingtonian, about his 'spooky' upbringing, (notwithstanding his comments about the abuse of memoir).

After this flurry of publishing activity, he returned to Hollywood with his teleplays for Judging Amy and Joan of Arcadia An old friend of his, Barbara Hall named the family Girardi in the series. A film adaptation of Vaporetto 13 was optioned for a film by Warner/Di Novi. In 2003, Roland Joffé, was ready to start filming his novella "Sunday Evenings at Contessa Pasquali’s", but quit.

When he came back to mystery fiction with The Wrong Doyle, it was with a small British publisher. Apparently, the reorganization, of Delacorte Press after the purchase of Random House by Bertelsmann, cooled their ardor for a well regarded novelist. Delacorte was repositioned as a young readers imprint. His books went out of print.

He was spring 2008 writer-in-residence at Goucher College.His novel, Gorgeous East couldn't get a review in The Washington Post.He was married to Linda Girardi; they have three children.He lives in an apartment on MacArthur Boulevard, Washington, D.C.

His manuscripts are held at Georgetown University.

Novels

1. Madeleine's Ghost, Delacorte Press (New York, NY), 1995.
2. A Novel of Adventure, Delacorte Press (New York, NY), 1997.
3. A Novel, Delacorte Press (New York, NY), 1997.
4. Seven Moral Tales, Delacorte Press (New York, NY), 1999.
5. The Wrong Doyle, Sceptre (London, England), 2002, Justin, Charles (Boston, MA), 2004.
6. Gorgeous East, St. Martin's Press, October 13, 2009, ISBN 9780312565862

Magazine Articles / Short Stories

1. "Nose Job", The New Republic, (November 13, 1995)
2. "The Dinner Party", TriQuarterly, Issue 99 (Spring/Summer 1997)
3. "Spooks on the Roof", Washingtonian, (April 2000)

Teleplays

1. "Imbroglio", Judging Amy, (2001)
2. "Vanity, Thy Name is Human", Joan of Arcadia, (First Aired 5/07/2004)

Criticism