|Portrayed by||Jon Michael Hill|
|First seen||Miss Taken|
|Residence||New York City, New York, U.S.|
|Significant other(s)||Mary Watson (wife)|
|Children||Joan Watson, Oren Watson|
Sometime before the beginning of the series Henry had an affair, Mary forgave him and they remained married. Joan later admits that she has had a hard time forgiving her father for his indiscretion. Henry makes an appearance in Season Four, Episode 7 "Miss Taken". Joan confronts her step father about a book he wrote, "The Heart Bled Blue", that features characters that are obviously based upon her and Sherlock Holmes. At first she demands that he have all of the books destroyed, but later forgives him and decides to help him with his second novel in the series, "The Heart Hit Home". In season five Joan shows these books to Marcus Bell and reveals that her step father wishes to write a more realistic crime novel and asks Marcus to meet with him.