Carl Aejemelaeus (20 May 1882 – 13 July 1935) was a Finnish colonel, modern pentathlete and fencer.

[1] Aejemelaeus was educated in St. Petersburg at the Nicholas Cavalry College [ru], Main Officer's Gymnastics and Fencing School [ru] and Imperial Archaeological Institute.

After the establishment of Finland's independence, he served as the First Adjutant of president K. J. Ståhlberg from 1919 to 1925 and was a military attaché in London and Moscow.

[2] Aejemelaeus competed for Russia at the 1912 Summer Olympics in the modern pentathlon.

[3] He was a member of Finnish Olympic Committee and a co-founder of the fencing club HFM Helsinki, which is the oldest fencing club in Finland.