Trivia

Robin Williams, a devoted fan of the original series, was interested in playing Gendo.

As an April Fools joke for 2009, USA and Canada distributor FUNimation Entertainment released a bogus but well known cast list for the main characters, in the vein of the success of the Hollywood cast in Afro Samurai: Resurrection (2009). It included Shia LaBeouf as Shinji Ikari, Lindsay Lohan as Rei Ayanami, Miley Cyrus as Asuka Langley Sohryu, Angelina Jolie as Misato Katsuragi, Samuel L. Jackson as Gendou Ikari, and Sean Penn as Pen Pen.

Co-director Kazuya Tsurumaki agreed to join the project on the condition that Hideaki Anno would have the third movie focus on "Rei 3" (the third Rei Clone).

Hideaki Anno opted to not return to his former employer of Gainax, whom he originally developed the show with for a few reasons. He felt it would be hard to bring in a fresh vibe at the studio that made it fearing the younger generation of staff would continue to hold back on expressing themselves out of deference to him as their senior and a strong desire to maintain better control over the budget and schedule, issues that plagued the original TV series when being co-produced at Tatsunoko. Despite this, he still allowed Gainax to come in and be given a share of the merchandising rights until about 2012 when Anno and his former colleagues had a greater falling out over unpaid royalties and other questionable business practices going on with Gainax, which culminated in a 2017 lawsuit.

The Rebuild films all follow a titling convention of jo-ha-kyu, which roughly corresponds to "beginning", "middle", and "end", originated in classical gagaku music and is best known to describe the acts of a noh play.