An American Aristocrat's Guide to Great Estates is a factual documentary television series commissioned by the Smithsonian Channel. It is presented by Julie Montagu, Countess of Sandwich, at the time of production, Viscountess Hinchingbrooke, the American wife of Viscount Hinchingbrooke (currently the Luke Montagu, 12th Earl of Sandwich), and explores the histories, management styles and upkeep costs of Britain's family mansions and castles.

Although initially recommissioned for a second series, it was subsequently cancelled due to a change at the top of the Smithsonian Channel. This resulted in Julie Montagu setting up a production company and through the Patreon crowdfunding platform, developing a new show called American Viscountess for YouTube.