Nice. The mathematical connection to some of these is pretty thin.

I'd add:

Jeffrey Kegler, The God Proof (novel about a lost manuscript of Kurt Gödel)

Norbert Wiener, The Tempter (novel about a patent troll math professor)

Martin Gardner, The Magic Numbers of Dr Matrix (other Martin Gardner books are there)

George Gamow, Mr. Tomkins in Wonderland (didactic about special relativity, there is other physics stuff on the list so why not)

Aleksandr Solzhenitsyn, The First Circle -- I haven't read this but I think it had a mathematician character

P. J. Plauger, Wet Blanket -- part of "Fighting Madness" series, about a physicst making universe-changing discoveries. The author is also a noted software developer who co-wrote at least two books with Brian Kernighan.

Maybe a bit out there, but Harry Potter and the Methods of Rationality, not mathematical per se but has mathematical asides, and is informed by statistics and game theory.

Others I'm not remembering, I'm sure.