Gregory Peck's summation speech, which runs for 6 minutes and 30 seconds, was nailed in a single take.
Mary Badham (Scout) and Gregory Peck (Atticus) became close during filming, and kept in contact for the rest of his life. Peck always called her "Scout", her character role, while Badham called Peck "Atticus".
Brock Peters, who played Tom Robinson in the film, delivered Gregory Peck's eulogy on the date of his funeral and burial, Monday, June 16, 2003.
After being offered the role of Atticus Finch, Gregory Peck quickly read Harper Lee's novel in one sitting and called director Robert Mulligan immediately afterwards to say that he would gladly play it.
The first scene that Gregory Peck shot showed him returning home from his character's law office while his children ran to greet him. Author Harper Lee was a guest on the set that day, and Peck noticed her crying after the scene was filmed. He asked Lee why she was crying, and she responded that Peck had looked just like her late father, the model for Atticus. Lee explained that Peck even had a little round stomach like her father's. "That's not a pot belly, Harper," Peck told her, "That's great acting."