A long-distance runner (5,000 m and 10,000 m), Ramjohn was the first to win a gold medal for Trinidad and Tobago at a major athletics event, the CAC Games in 1946.
He was also part of the first group of five athletes to represent Trinidad and Tobago in the Olympic Games (1948).
In this capacity he was one of 12 representatives from Trinidad and Tobago at the coronation of King George VI and Queen Elizabeth.
Ramjohn was awarded the Humming Bird Medal (Silver) for Social Work and Sport by the government of Trinidad and Tobago.
Ramjohn's career included the following significant accomplishments: Manny Ramjohn was the cousin of former President of Trinidad and Tobago Noor Hassanali and of former First Lady Dr. Jean Ramjohn-Richards, wife of President George Maxwell Richards.