Kennedy Kane "Ken" McArthur (10 February 1881 – 13 June 1960) is most noted as a track and field athlete and winner of the marathon at the 1912 Summer Olympics.

McArthur ran his first marathon late in the 1908 season, and surprisingly beat the Olympic silver medalist Charles Hefferon.

Representing South Africa in the event, McArthur and his teammate Christian Gitsham ran together and soon took the lead.

Confident of victory, Gitsham stopped for water, expecting his colleague to join him, as agreed.

In the next season, McArthur injured his foot in an accident and was forced to retire from athletics.