Despite widely published reports that Angelina Jolie Pitt was originally cast as the lead, but dropped out, Luc Besson has since denied them and admitted that he only met with a couple of actresses to discuss playing the lead role. He says when he saw how strongly Scarlett Johansson reacted to the story, she immediately landed the part.
In an interview on 8 March, 2014, (evening news on France 2), Luc Besson said that this project took 10 years to become a reality. Also, he admitted that he knew that some scientific assumptions were erroneous, e.g. that humans use only 10% of their brain. Nonetheless, he said that "[such an assumption] would be a great start for a sci-fi movie".
The human-looking ape seen in some scenes is Australopithecus afarensis, who represents the 'missing link' between apes and humans, nicknamed 'Lucy' after John Lennon's song "Lucy in the Sky with Diamonds." She lived 3.2 million years ago and is the earliest known hominid to walk upright like humans.
In 2014, Lucy is the most successful French movie outside of France for the past 20 years, when UniFrance started creating statistics about French movies. With 463 million dollars, 52.1M admissions outside of France, and 5.2M admissions in France, Lucy was more successful than Taken 2, The Fifth Element and Intouchables.
A young tattoo artist is seen sporting a very Mexican Lady of Guadalupe/Holy Death tattoo on her back. This mystery girl is also seen being tattooed in the movie 3 Days to Kill. Both films were written by Luc Besson. The tattooed model is not credited in any of the films.
In 1974, Donald C. Johanson discovered a 3.2 million year old skeleton in Ethiopia. He called it Australopithecus Afarensis, later nicknamed "Lucy" In the movie, the lead character Lucy is played by Scarlett Johansson. (Despite the similarities of their surnames, the two are not related.)
At the beginning of the movie, when Lucy is being approached by the Korean thugs, the scene changes several time to footage of a cheetah chasing down and catching an gazelle. Lucy is wearing a cheetah-print jacket at the time.
The trivia item below may give away important plot points.
When prehistoric Lucy reaches her hand out to touch the other Lucy's hand, their hand/finger positions mirror the hand positions of Adam reaching out to touch the Hand of God in, "The Creation", by Michelangelo as painted on the ceiling of the Sistine Chapel, in Rome. Metaphorically, Lucy at 100% brain capacity could be seen as God, while prehistoric Lucy could be seen as an Adam figure.