Robert Brown Parker (September 17, 1932 – January 18, 2010) was an American writer of fiction, primarily of the mystery/detective genre. His most famous works were the 40 novels written about the private detective Spenser. ABC television network developed the television series Spenser: For Hire based on the character in the mid-1980s; a series of TV movies based on the character were also produced. His works incorporate encyclopedic knowledge of the Boston metropolitan area. The Spenser novels have been cited by critics and bestselling authors such as Robert Crais, Harlan Coben, and Dennis Lehane as not only influencing their own work but reviving and changing the detective genre.

Parker also wrote two other series based on an individual character: He wrote nine novels based on the character Jesse Stone and six novels based on the character Sunny Randall. Parker wrote four Westerns starring the duo Virgil Cole and Everett Hitch. The first, Appaloosa, was made into a film with Ed Harris.