Wikipedia
Lilou is a French female given name. It is rising in popularity in France, where it is ranked in the top 50 names given to baby girls. It may have originated as a short form of names ending in the sound "lee" such as Aurélie, Amélie, Aline, Élise, Élie, Coralie, or Liliane, following the French way of forming short forms of names by adding the suffix "ou" to affectionate names. It is also said to be an Occitan language version of the name Lily, originally spelled Liló in that language. It was not registered as a formal name in France prior to 1997, when 19 girls named Lilou, nine girls named Leeloo and four girls named Leelou were registered. The spelling Lylou is also used. Short forms of names have become increasingly popular as formal names in France as well as elsewhere in Europe.
It is still a rare name in other countries. In the United States, just ten girls were given the name in 2009. The name was also given to 10 American girls in 2010, to 11 American girls in 2011 and to 17 American girls in 2012. Thirty-two newborn girls were given the name in French-speaking Quebec in 2012.
Actress Milla Jovovich played a character called Leeloo in the 1997 French science fiction/fantasy film " The Fifth Element", which might also have influenced use of the name in France.