John Cromwell is an actor and producer and is most well known for his acts in Memorial Day (2012), Dust of War (2013), Sweethearts (2014) and his work on American Horror Story, playing the young Arthur Arden. He stands an inch taller than his father. He and his father have played the same character the same time, three times: In Memorial Day, which aired in 2012, American Horror Story: Asylum, which was in 2012, however, he went on to portray the character again in another season without his father, and Betrayal, a tv series which played within the course of 2013 - 2014.
- He is the son of actor, James Cromwell, who played the older Arthur Arden in season two.
- John Cromwell is one of the eight cast members that portrayed the same character in different seasons. He portrayed a young Dr. Arden in both Asylum and Freakshow. The others are Lily Rabe, Sarah Paulson, Gabourey Sidibe, Christine Estabrook, Matt Ross, Naomi Grossman and John Carroll Lynch.