The Australian Shortland, 49, is best known for the 2012 Nazi drama Lore, which she also co-wrote.
"Some of the names considered to helm "Black Widow" were Amma Asante ("Belle, A United Kingdom"), Maggie Betts (Novitiate"), Melanie Laurent ("Galveston") and Kimberly Pierce ("Boys Don't Cry").
Best known for her work on Lore and Berlin Syndrome, Shortland was chosen apparently because she "had a fan in Johansson, who pushed for the helmer".
Shortland made her directorial debut with Somersault (2004). The Black Widow screenplay will be written by Jac Schaeffer, who most recently authored the script for Nasty Women, the gender-swapped remake of Dirty Rotten Scoundrels.
Black Widow, who first appeared in Iron Man 2 and has since been a vital part of the Avengers films since, has always been the subject of online support for a solo film of her own.
Scarlett first played the role in 2010's Iron Man 2, and she's confident that the character's "tortured past" would make for an entertaining standalone film.