Literature
- The Dresden Files: In "Love Hurts," Murphy's line about disliking coincidence is very similar to a common phrase used by Spenser. This is further established when Harry comments on Murphy's dislike of "reading Parker." (There's actually a very strong Parker influence on The Dresden Files in general; the often-used blurb of "Spenser crossed with Merlin" is very apt, and author Jim Butcher has specifically identified Parker as his favorite author.)
Live Action TV
- Leverage: "The 10 L'il Grifters Job" includes shout-outs to all manner of detective stories and Eliot himself is practically a shout-out to the Spenser novels.
- Psych: Shawn himself can be taken as one big homage. Let's see: a smart mouthed guy named Spencer is too wild to be a cop but he's a great detective, so he and his best friend found a private detective agency where they take on cases that tend to become vastly more elaborate than they first seemed. I wonder where they got that idea.
Western Animation
- The Boondocks: In the episode A Date with the Health Inspector Gin Rummy mentions Spenser For Hire.