Born and raised in Plantation, Florida, of Norwegian heritage, Hiaasen was the first of four children and the son of a lawyer, Kermit Odel, and teacher, Patricia. He married Connie Lyford just after high-school graduation and entered Emory University in 1970, where he contributed numerous satiric pieces to the school newspaper, The Emory Wheel. In 1972 he transferred to the University of Florida, where he wrote for The Independent Florida Alligator. Hiaasen graduated in 1974 with a degree in journalism. Carl and Connie divorced in 1996, and he married Fenia Clizer in 1999. He has one son from each of his two marriages.

He was a reporter for Cocoa Today (Cocoa, Florida) for two years beginning in 1974, then was hired by the Miami Herald in 1976, where he still () works. In 1979 he switched to investigative journalism, initially focusing on property development and the construction industry, exposing schemes to despoil the natural beauty of Florida for profit; several of his novels have plots based on such themes. He began writing a regular column in 1985; initially three times a week, but after the success of his novels, he cut back to weekly.

After becoming an investigative reporter, Hiassen began to write novels. His first three were co-written by fellow journalist Bill Montalbano: Powder Burn (1981), Trap Line (1981), and A Death in China (1986). Montalbano accepted a job as a foreign correspondent in 1986 and Hiaasen wrote his first solo novel, Tourist Season, where most of the themes and style used in subsequent books were introduced.

Hiaasen's fiction mirrors his concerns as a journalist and Floridian. His novels have been classified as "environmental thrillers" and are usually found on the mystery shelves in bookshops, although they can just as well be read as mainstream reflections of contemporary life. His books have been published in 33 different languages.

He said this about Florida: "The Sunshine State is a paradise of scandals teeming with drifters, deadbeats, and misfits drawn here by some dark primordial calling like demented trout. And you'd be surprised how many of them decide to run for public office."

Hiaasen's Florida is a hive of greedy businessmen, corrupt politicians, dumb blondes, apathetic retirees, intellectually challenged tourists, hard-luck redneck cooters, and militant ecoteurs. It is the same Florida of John D. MacDonald and Travis McGee, but aged another 20 years and viewed with a more satiric or sardonic eye.

Hiaasen's first venture into writing children's novels was Hoot, which received the Newbery Honor Award and was made into a movie, with Jimmy Buffett playing the role of a classroom teacher. Hiaasen's second children's novel was Flush, and his most recent was Scat. Hiaasen's young adult novels follow the theme of environmental issues. They also have his characteristic unique characters and some theme of adventure.

Hiaasen worked for several years with British theatre producers for the adaptation of his bestseller Lucky You; the resulting play includes music by Loudon Wainwright III, and premiered at the Edinburgh Festival Fringe 2008.

In addition to writing, Hiaasen also does speaking engagements and lectures.

Fiction

Adult Fiction

• Tourist Season (1986)
• Double Whammy (1987)
• Skin Tight (1989)
• Native Tongue (1991)
• Strip Tease (1993) (filmed in 1996 as Striptease by Andrew Bergman, starring Demi Moore and Burt Reynolds)
• Stormy Weather (1995)
• Lucky You (1997)
• Naked Came the Manatee (1998) (Collaboration with 12 other authors)
• Sick Puppy (2000)
• Basket Case (2002)
• Skinny Dip (2004)
• Nature Girl (2006)
• Star Island (2010)

With Bill Montalbano

• Powder Burn (1981)
• Trap Line (1982)
• A Death in China (1984)

Young Adult Fiction

• Hoot (2002) (young adult novel) (released as a movie in May 2006 by director Wil Shriner)
• Flush (2005) (young adult novel)
• Scat (2009) (young adult novel)

Short stories

• " Tart of Darkness" (2003, Sports Illustrated Swimsuit Issue)

Non-fiction

• Team Rodent: How Disney Devours the World (1998)
• Kick Ass (1999)
• Selected Columns (2001)
• The Downhill Lie (2008)

Collections

• A Carl Hiaasen Collection (2000) (an audiobook set containing Tourist Season, Stormy Weather, and Strip Tease)

"Hoot," Hiassen's first book for young readers, has won both a Newbery Honor from the Association for Library Service to Children and won the 2005 Rebecca Caudill Young Readers' Book Award, selected for the latter honor by school-age children (grades 4-8) in the U.S. State of Illinois.