The chapter covers issue of freedom of expression in sport in non-state sports sector. In other words, to what extent it is possible to invoke freedom of expression against non-state actors, since freedom of expression is guaranteed in actions against the State. In the chapter there are examples of case-law of European Court of Human Rights and the United States courts, resolving to what extent non-state actors act under authority of the State in order State action condition is fulfilled for application of freedom of expression in a particular case. Examples include Olympic sector and for comparison Court of Arbitration for sport (CAS) as well. Some forms of expressions of athletes and fans are described and evaluated to what extent they can be prohibited in the best interest of sport.