He said the Nollywood film industry was doing well but unless it was backed, it would be "ruined by pirates".
The industry is worth $5bn (Â£3bn), but filmmakers still struggle to make a profit because of piracy.
Despite being hastily shot on low budgets, their focus on love, betrayal and witchcraft is hugely popular across Africa.
President Buhari ordered security agencies to identify those involved in copyright piracy and bring them to justice.
Nollywood is not the only industry affected by the problem.
Producers in Kannywood - the Hausa language film industry based in the northern city of Kano - are also complaining and had asked the president to intervene.
Mr Buhari said he would do everything possible to protect the entertainment industry.
"They [film producers] have built an industry with their own sweat", he said.
"It is therefore incumbent on us to give them the necessary support."
Nigeria's film industry analysts believe that Nollywood is churning out up to 50 films a week.
However, most of these movies are sold straight to DVD and filmmakers struggle to make a profit.
Nigeria's President Muhammadu Buhgari has vowed to save the country's entertainment industry from pirates.