Dedicated to the memory of Amy Lehrhaupt, the woman who was the inspiration for Before Sunrise (1995). Richard Linklater had spent a night walking and talking around Philadelphia with her in 1989. Though initially they stayed in touch over the telephone, they lost contact eventually. In 1994, Linklater started shooting "Before Sunrise" and when the world premiere was about to take place, Linklater was secretly hoping that Amy would show up but she did not. Ten years later, Linklater shot the sequel Before Sunset (2004) and had yet to hear from Amy. Finally, in 2010, a friend of Amy's who knew about their story, contacted Linklater to tell him that Amy had died in a motorcycle accident on May 9, 1994 at the age of 24 and even a few weeks before he started shooting Before Sunrise (1995). Both Linklater and Hawke were devastated but found comfort in the inspiration for the Before Trilogy.
In the final scene of Before Sunset (2004), Celine and Jesse discuss their admiration for Nina Simone and Celine dances to "Just in Time." In this film, one of their daughters is named Nina. The name of the other daughter, Ella, is likely a reference to Ella Fitzgerald.
Richard Linklater, Julie Delpy and Ethan Hawke have all agreed on interviews that the final thing that made them decide to make the movie was the fact that the three of them are parents and could know how to write that into the characters' live.
Richard Linklater, Ethan Hawke and Julie Delpy had an idea to just show Jesse and Celine on a typical day: Someone goes and picks up the kids and it's only later at night that they have this together moment which actually was one of the original ideas behind the title.
Like the previous films of the trilogy, the film includes reference to James Joyce: When Céline recalls a black-and-white film from her teenage years which had a powerful impact on her, particularly a scene in which a couple visit Pompeii and see the bodies mummified by the volcanic explosion. She doesn't name the film, but it is Viaggio in Italia (1954) which is loosely based on James Joyce's short story, 'The Dead'.
The house where they are staying is the famous residence of the late British travel writer Sir Patrick Leigh Fermor, in Kalamitsi, near Kardamili, southern Peloponnese. He left it to the Benaki Foundation on his death in 2011, and the Foundation loaned it to the production. The character of "Patrick" is clearly a nod to the great writer and Hellenophile.