Samar Banerjee began his football career with the Bali Prativa Club in 1948 and moved to the Bengal Nagpur Railway Club the following year. At the same, he entered the R. G. Kar Medical College, but after helping the Railway Club get promoted to the Premier Division, he was recruited by Mohun Bagan AC and abandoned his studies to pursue a career in football. During his time with Mohun Bagan (1952-1959), he won the Calcutta Football League four times (1954-1956, 1959), the IFA Shield three times (1952, 1954, 1956), the Durand Cup in 1953 and 1959, and the Rovers Cup in 1955. He joined the Indian national team in 1954 and, two years later, was the captain of the squad that lost the bronze medal match against Bulgaria at Melbourne Olympics. Following his retirement from active competition, he worked as a coach and selector.