MacDonald has published forty-seven novels outside the Travis McGee series. Many of them seem to take place in other corners of the same world McGee occupies; indeed, some overlap with McGee's world explicitly.

The Last One Left (1967), for example, involves the history of the Munequita, a small runabout found adrift in the Gulf Stream; in the next year's Pale Gray for Guilt, McGee has bought the same boat in an estate sale. In addition, The Last One Left is dedicated to Travis McGee!

Similarly, The Lonely Silver Rain (1985) includes a passing reference to TV preacher John Tinker Meadows, a central character of One More Sunday.