Kai Setälä, Finnish physician and professor (died 2005)

Kai Martin Edvard Setälä was a Finnish physician and professor of pathological anatomy at the University of Helsinki. Through his daughter Christel, he was the maternal grandfather of Alexander Stubb, the 13th President of Finland. Setälä himself was the great-nephew of professor E. N. Setälä (1864–1935), the Counsellor of State, the Chairman of the Senate of Finland and co-author of the Finnish Declaration of Independence.

September 13 is the 256th day of the year in the Gregorian calendar; 109 days remain until the end of the year.