Rachel Weisz as Melina Vostokoff aka Black Widow: She is a highly specialized spy agent who has been through the Red Room training program four times.
Florence Pugh as Yelena Belova aka Black Widow: A product of the ruthless Red Room training program, she holds a secret history with Black Widow and is determined to solve.
Scarlett Johansson as Natasha Romanoff aka Black Widow: Separated from the now fractured Avengers, she is faced with the dark path that led to her becoming a spy and assassin and the events that followed.
Deep down, he feels guilty about his life as a spy, especially towards Natasha Romanoff, whom he met long before she became Black Widow.