1889 U.S. National Championships – Men's singles

Defending champion Henry Slocum defeated Quincy Shaw in the Challenge Round, 6–3, 6–1, 4–6, 6–2 to win the men's singles tennis title at the 1887 U.S. National Championships. Shaw defeated Oliver Campbell in the All Comers' Final, 1–6, 6–4, 6–3, 6–4. The event was held at the Newport Casino, Newport, R.I. from August 21 to August 28.