Nelson Marcelo San Martín Arriagada (born 17 May 1980) is a Chilean former professional footballer who played as a midfielder.

[2] The former Universidad de Chile midfielder who began to pitch his tent in Alor Star in November 2006 has been playing an influential role for Kedah FA.

In his first year at his new club, he managed to capture the eyes of most Kedah FA fans with his superb passing and vision, and also with an excellent free kick delivery.

Alongside his teammates, Ahmad Fauzi Saari, Marlon Alex James, Mohd Khyril Muhymeen Zambri, they played the most attractive football in Malaysia.

After his departure from Malaysia, Nelson went to neighbors Thailand and played 1 season with Bangkok Glass and later on relocated to Singapore in order to join Home United FC in a 6-month contract.