Movie based on one of the lower caste tribes of Kerala called Odiyans, said to have been the first "quotation gangs" (hired criminals), who went disguised as animals during night hours to attack their enemies.
Bollywood actor 'Amithab Bachchan' was the original choice for the role of grandfather for Mohanlal's character. When the production began he was replaced by Tamil actor Sathyaraj. Finally Hindi actor Manoj Joshi was ultimately cast for the role. Odiyan was Manoj Joshi's debut Malayalam movie.
The script writer got the plot idea when he was lecturing journalism classes; he asked the students to write a feature story to test their creativity. The subject was "if Hollywood director Steven Spielberg comes to Kerala to meet the last Odiyan". The word "last" was registered in his mind and became the plot point in his screenplay. His story is about the last surviving Odiyan and the reasons his clan is almost extinct.
South Indian editor A. Sreekar Prasad was going to join the film, but he he was later replaced by Johnkutty in the last minute. Production designer Sabu Cyril was replaced by Prashanth Madhav. Actor Appani Sarath was about to join the cast, but he got replaced at the last moment.
In order to play the role of a younger version of his character, lead actor Mohanlal reportedly lost around 18 kilograms (40 lbs.) over a span of 51 days through a strict diet and physical training program.