Konstantin Dmitrievich Nabokov (November 28, 1871, Poland, March 18, 1927, Greater London, England) was a Russian diplomat who worked in England. His name in English appears as Constantine and Konstantin, as the French spelling was common among diplomats of that time. The surname Nabokov also has different spelling variations in various sources.

After the death of Count Benckendorff in 1917, Nabokov took his place as the Russian ambassador in London. In September 1919, he had to resign, but he continued to actively work for the Russian community through the Russian Red Cross. Later, he was assigned to diplomatic service in Norway; however, in the mid-1920s, he returned to England and settled there. Konstantin Nabokov was the uncle of the famous writer Vladimir Nabokov.