He is nostalgic for the past and has a close relationship with Violet Crawley, Dowager Countess of Grantham as well as Elsie Hughes. He also loves Lady Mary Crawley almost as a surrogate daughter.
As a young man, Carson was briefly on the stage, (or "on the halls" as his former colleague, Charles Grigg said), as a double act called, The Cheerful Charlies.

Carson is a man who takes his job seriously. He is very strict about the standards at Downton, and gets really upset whenever they are disrupted or breached by his coworkers. However, he does have a deep respect and admiration for the Crawley family and others of the "upstairs" world. Mrs. Hughes accuses him of worshiping them.[2] Despite his stern exterior, he shows almost fatherly concern for his coworkers. Thomas is surprised to see him teaching Alfred about spoons, as he had never done anything like this for Thomas. Carson replied that Thomas had never asked. Though he is determined that they ensure that the house is run efficiently, and they never seek to cause trouble. He is initially against the employment Mr. Bates because he believes that his lameness will cause dissension as others will have to do his work for him, but later admitted he could not imagine Downton without him. Like Lord Grantham, he has difficulty accepting change and takes great pride in Downton Abbey and what it symbolizes. Despite his personal beliefs, he will put the honor of the house before them, such as loathing Thomas Barrow's homosexuality, but wishing to see him go quietly without bringing scandal to the house.

He can however be a surprisingly kind man, such as when he called Tom's respect for Cora's invitation for Kieran Branson "exemplary" and when he shows a preference for Alfred over Jimmy even though Jimmy has had more experience as a footman than Alfred despite being angry at Alfred for his past errors. To those he is close too, he is always extremely concerned when they might be in serious trouble, such as when Mrs. Hughes might have had cancer. He also has a very loving side, such as when he comforts Lady Sybil's daughter.

Politically, Carson is a monarchist, loyal to and proud of the English monarchy.