The film, called Mr Holmes, sees the sleuth living in seclusion by the sea with his housekeeper and her young son who help him attempt to solve his final case.
The story, based on the novel A Slight Trick of the Mind by Mitch Cullin, is directed by Bill Condon who worked with Sir Ian on Oscar-winning Gods and Monsters.
Sir Ian said: "Sherlock Holmes at 93 is retired, still solving mysteries: but here's the sting - he also keeps bees. So many splendid actors have already played the part but none of them had Bill Condon directing. I'm the lucky one: and I'm excited."
American actress Laura Linney will play Holmes' housekeeper Mrs Munro in a cast that also includes Roger Allam, Phil Davis and Frances de la Tour.
Holmes has been played in recent years by Benedict Cumberbatch in the BBC1 update of the stories, Robert Downey Jr in two film outings and Jonny Lee Miller has portrayed him in US TV series Elementary.