Trivia: Zack Snyder didn't want to call the film "Batman v Superman." He and writer Chris Terrio pitched multiple other titles first. Snyder wanted something more flowery, like "Son of Sun and Knight of Night, " which the studio absolutely hated, while Terrio suggested titles like "Justice League: Foundations," since it was showing how the first members of the Justice League came together. The studio wanted something more straightforward and marketable, and "Batman v Superman" was eventually picked.
Trivia: During the big fight between Batman and Superman, a broken window has the same shape as Ontario, in Canada. Superman creator Joel Shuster was born in Toronto. The broken window is only ever shown from Superman's angle, not Batman's. This was confirmed by Zack Snyder as being a deliberate, if obscure, easter egg.
Trivia: During Batman and Superman's fight scene, there is a shot of some graffiti that says "Quis custodiet ipsos custodes?", which is Latin for, "Who watches the watchers?" This is a reference to "Watchmen", which was also directed by Zack Snyder, and also references the theme of both films.
Trivia: In a deleted scene near the end of the film after Luthor is arrested, a guard calls Luthor prisoner AC231940 and tells him to turn around. Action Comics #23 was Lexus Luthor's first appearance in 1940.