Laurence Doherty defeated the two-time defending champion William Larned in a rematch of the previous year's Challenge Round, 6–0, 6–3, 10–8 to win the men's singles tennis title at the 1903 U.S. National Championships.[2] Doherty had defeated William Clothier in the All Comers' Final, which was delayed by a day due to rain.[3][4]
The event was held at the Newport Casino in Newport, R.I., United States.[1][5] The entry list consisted of 97 players, which was slightly smaller than that of the previous year.