The purpose of this essay is to analyze and determine if the National Security Law implemented in Hong Kong is in contradiction or in accordances with John Stuart Mill’s four grounds of free speech. What contradictions or accordances can be found between the law and the four grounds of free speech? The theoretical background for this essay consists of information about the relation between Hong Kong and China, the law and its contents, definition of the four grounds of free speech and the protection of free speech in other forms. A qualitative content analysis was done with the use of a systemic analysis to achieve the purpose. The findings where categorized according to the four grounds of free speech. The essay concludes that all the four grounds are contested. This is due to the law granting the government of Hong Kong and its various bodies additional power to control and supervise what is spoken and written. One instance of accordance was found between the law and the four grounds. Furthermore, the right to freedom of speech will diminish on various levels across the region of Hong Kong and the criminalization of an opinion has effectively been instated by the law.