In British English 'sport' is the general term and is an uncountable noun.
For example: (1) He is not interested in sport. (2) There is too much sport on television. (3) She excels at sport.
If it refers to particular types of sport, the term 'sport/s' (a countable noun) is used.
For example: (1) Bobby's sport is tennis. (2) My favourite sports are tennis and hockey.
In American English, 'sports' is a plural noun.
For example: He likes watching sports on television.