There is actually no one that can permanently or completely calm The Hulk. The Hulk is a fictional character in Marvel Comics and is known for his incredible strength and immense size, as well as his anger management issues. However, in some instances, psychologists, such as Leonard Samson and Doctor Strange, have been able to temporarily calm The Hulk through different forms of therapy or magic. Several characters in the Marvel Universe have also shown the ability to calm The Hulk down by talking to him, including Black Widow and Captain America.