Kennedy Kane "Kenneth" McArthur (February 10, 1881 - June 13, 1960) was a South African athlete, winner of the marathon race at the 1912 Summer Olympics.

Kenneth McArthur, after winning the Stockholm Olympic marathon

Born in Ballymoney, County Antrim, Northern Ireland, Kenneth McArthur was recognised as a promising athlete as a teenager, but he didn't yet pursue an athletics career and chose to emigrate to South Africa in 1901.

McArthur begun to take athletics seriously after joining the Johannesburg Police Force in 1906. Soon he had won the Transvaal half and one mile championships, the five mile track championship and also two national cross country championships. McArthur ran his first marathon late in the 1908 season, and surprisingly beat the Olympic silver medalist Charles Hefferon. He also won the national one and ten mile championships.

The Stockholm Olympic marathon took place in sweltering heat. 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. Instead McArthur ran on, stretching his lead and taking him to certain victory over Gitsham by 58 seconds.

In the next season, McArthur injured his foot in an accident and was forced to retire from athletics. He ran six marathon races (including the Olympic marathon) throughout his career and never lost one. Kenneth McArthur died in Potchefstroom at the age of 79.