Elba, 43, will play gunslinger with McConaughey, 46, portraying the mystical foe known as the man in black, reported Entertainment Weekly.
"The thing is, it's been a long trip from the books to the film. When you think about it, I started these stories as a senior in college, sitting in a little cabin beside the river in Maine, and finally this thing is actually in pre-production now. I'm delighted, and I'm a little bit surprised," King said.
"What Stephen King does best is mixing the everyday, or what you might call the mundane, with the fantastical. In my view, (The Dark Tower) novels are a mix between sci-fi and fantasy and modern times. That exact mix is so Stephen King," Arcel said.
The six-shooter-and-sorcery tale which spans eight novels, assorted comic books and short stories, is frequently referenced throughout King's body of work.