Morrell decided to become a writer at the age of 17, after being inspired by the writing in the classic television series Route 66. Morrell moved to the United States in 1966 to study with Hemingway scholar Philip Young at Pennsylvania State University, where he would eventually receive his M.A. and Ph.D. in American literature. During his time at Penn State he also met science fiction writer Philip Klass, better known by the pseudonym William Tenn, who taught the basics of writing fiction.

Morrell began work as an English professor at the University of Iowa in 1970. In 1972, his novel First Blood was published; it would eventually be made into the 1982 film of the same name starring Sylvester Stallone as Vietnam veteran John Rambo. Morrell continued to write many other novels, including The Brotherhood of the Rose, the first in a trilogy of novels, which was adapted into a 1989 NBC miniseries starring Robert Mitchum. Eventually tiring of the two professions, he gave up his tenure at the university in 1986 in order to write full time.

Morrell's teenaged son Matthew died of Ewing's Sarcoma, a rare form of bone cancer in 1987. The trauma of his loss influenced Morrell's work, in particular in his exciting creative fiction memoir about Matthew, Fireflies. The protagonist of Morrell's novel Desperate Measures also experiences the loss of a son.

Morrell is the co-president of the International Thriller Writers organization.

Morrell is a graduate of the National Outdoor Leadership School for wilderness survival as well as the G. Gordon Liddy Academy of Corporate Security. He is also an honorary lifetime member of the Special Operations Association and the Association of Former Intelligence Officers.

According to his website, he has been trained in firearms, hostage negotiation, assuming identities, executive protection, and anti-terrorist driving, among numerous other action skills that he describes in his novels. He recently received his FAA licence to pilot his own small plane.

Morrell lives in Santa Fe, New Mexico.

Fiction

• 1972 First Blood
• 1975 Testament
• 1977 Last Reveille
• 1979 The Totem
• 1982 Blood Oath
• 1983 The Hundred-Year Christmas - illustrated by R. J. Krupowicz
• 1984 Brotherhood of the Rose
• 1985 Fraternity of the Stone
• 1985 First Blood Part II - novelization of the film of the same name
• 1987 The League of Night and Fog
• 1988 Rambo III - novelization of the film of the same name
• 1990 Fifth Profession
• 1991 The Covenant of the Flame
• 1993 Assumed identity
• 1994 Desperate Measures
• 1994 The Totem - unabridged
• 1996 Extreme Denial
• 1998 Double Image
• 1998 Front Man
• 1999 Black Evening
• 2000 Burnt Sienna
• 2002 Long Lost
• 2003 The Protector
• 2004 Nightscape
• 2005 Creepers
• 2007 Scavenger
• 2008 The Spy Who Came for Christmas
• 2009 The Shimmer

Nonfiction

• 1976 John Barth: An Introduction
• 1988 Fireflies
• 2002 Lessons from a Lifetime of Writing: A Novelist Looks at His Craft

Comic books

• 2007 - 2008 Captain America: The Chosen