Karl Magnus Wegelius (20 August 1884 – 9 December 1936) was a Finnish multi-sport athlete who won five Olympic medals and eight Finnish national championships in sport shooting, gymnastics, and track and field athletics.

[3] In track and field athletics, he won two Finnish national championship golds 4 × 100 metres relay and 1600 metre medley relay, both in 1910, representing the club Porin Tarmo.

[4] He was a treasurer and a vice president of Finnish Shooting Sport Federation.

[5] He performed his matriculation exam in Tampere Real Lycaeum in 1905 and graduated as a diplomi-insinööri from the Helsinki University of Technology in 1909.

[5] He died in the 1936 KLM Croydon accident while on a business trip to England.