Mr. Carroll is the father of Mary Carroll, the young patient in Kids. He is married to Mrs. Carroll. He is portrayed by actor Dylan Kussman.
Mr. Carroll is called to the hospital when Mary's condition starts to get worse. He and his wife arrive a few hours after she is admitted.
They finally diagnose Mary with thrombotic thrombocytopenic purpura caused by pregnancy. Mr. Carroll asks House why she needs surgery to treat it and presses the matter when House is evasive. However, House refuses to breach patient confidentiality. Later, however, Mary tells her parents on her own.