Namesakes
Konstantin
(m) 1186-1218 
Russian Grand Dukes and Tsars 1216-1218
Konstantin I
(m) ?-1277
Bulgarian Kings and Tsars 1257-1277
Konstantin II
(m) c. 1370-1422
Bulgarian Kings and Tsars 1397-1422
Konstantin Stoilov
(m) 1853-1901
Bulgarian Presidents and Prime Ministers 1887; 1894-1899 (prime minister)
Konstantin Tsiolkovsky
(m) 1857-1935
Notable Scientists and Inventors
Konstantin Stanislavski
(m) 1863-1938
Notable Actors and Entertainers (actor)
Notable Filmmakers
Konstantin Päts
(m) 1874-1956
Estonian Presidents and Prime Ministers 1921-1922; 1923-1924; 1931-1932; 1932-1933; 1933-1934; 1934-1937; 1938-1940 (state elder/prime minister/president)
Elmer Niklander
(a.k.a. Konstantin) (m) 1890-1942
Olympic Medalists 1912; 1920 discus throw - both hands; shot put - both hands; discus throw; shot put (bronze/gold/silver)
Konstantin Muraviev
(m) 1893-1965
Bulgarian Presidents and Prime Ministers 1944 (prime minister)
Konstantin Rokossovsky
(m) 1896-1968
Notable Military Figures
Konstantin Chernenko
(m) 1911-1985
Other Leaders 1984-1985 Soviet Union (general secretary)
Konstantin Volkov
(m) 1960-
Olympic Medalists 1980 pole vault (silver)
Konstantin Lavronenko
(m) 1961-
Notable Actors and Entertainers (actor)
Konstantin Novoselov
(m) 1974-
Nobel Prize Winners 2010 (physics)
Notable Scientists and Inventors
Konstantin Dubrovin
(m) 1977-
Olympic Medalists 1996 swimming - 4x200 m freestyle relay (bronze)
Konstantin Ushkov
(m) 1977-
Olympic Medalists 1996 swimming - 4x100 m freestyle relay (silver)
Costa Ronin
(m) 1979-
Notable Actors and Entertainers (actor)
Konstantin Kravchuk
(m) 1985-
Notable Athletes (tennis)