It will be the first time the group has appeared at the three-day event staged near Beauly in the Highlands.
The festival will take place from 3 until 5 August in 2017.
Organisers said Scots singer KT Tunstall would support Franz Ferdinand. Seventies disco legends Sister Sledge are to headline on the Thursday night.
Promoter Joe Gibbs said: "This is the first time Franz Ferdinand has played Bella and we are totally delighted to welcome them to our stage.
"I couldn't think of a better act to close out the festival.
"And we are thrilled to be welcoming KT back. She played Bella before as an unannounced special guest but we are pleased to have properly on the bill this time."
Glasgow rock band Franz Ferdinand have been confirmed as the Saturday night headliners at next year's Belladrum Tartan Heart music festival.