A number of instruments protect the right to freedom of opinion and expression under human rights law. Article 19 of the Universal Declaration of Human Rights, adopted by the UN in 1948, provides the following:

Everyone has the right to freedom of opinion and expression; this right includes freedom to hold opinions without interference and to seek, receive and impart information and ideas through any media and regardless of frontiers.

While the Universal Declaration did not itself establish binding obligations on States, it has set the standard for human rights law ever since.

Nearly twenty years later, States adopted the International Covenant on Civil and Political Rights, which adapted the Universal Declaration’s protections in its own version of Article 19:

1. Everyone shall have the right to hold opinions without interference.

2. Everyone shall have the right to freedom of expression; this right shall include freedom to seek, receive and impart information and ideas of all kinds, regardless of frontiers, either orally, in writing or in print, in the form of art, or through any other media of his choice.

3. The exercise of the rights provided for in paragraph 2 of this article carries with it special duties and responsibilities. It may therefore be subject to certain restrictions, but these shall only be such as are provided by law and are necessary: (a) For respect of the rights or reputations of others; (b) For the protection of national security or of public order (ordre public), or of public health or morals.

The Covenant also includes a provision not found in the Universal Declaration, providing in Article 20 a basis for States to prohibit “propaganda for war” and “advocacy of national, racial or religious hatred that constitutes incitement to discrimination, hostility or violence.” Relevant resolutions of the Human Rights Council focusing on Article 20 may be found at A/HRC/RES/16/18 and A/HRC/RES/25/34, supported by an important experts’ document known as the Rabat Plan of Action. The Human Rights Council and General Assembly have also adopted freedom of expression resolutions in particular focus areas, such as the safety of journalists (A/HRC/RES/21/12,  A/RES/68/163 , and the UN Plan of Action on the Safety of Journalists and the Issue of Impunity); freedom online (A/HRC/RES/20/8 , A/HRC/26/L.24; and privacy (for instance, A/RES/68/167).

On July 21, 2011, the UN Human Rights Committee adopted General Comment 34 on States parties’ obligations under Article 19 of the International Covenant on Civil and Political Rights (ICCPR). As Article 19 provides a basic legal standard on the right to freedom of opinion and expression, General Comment 34 provides guidance to States on what this freedom means, and therefore strengthens the protections provided by international law.

General Comment 34 (PDF)

Regional instruments also protect the rights to freedom of opinion and expression. Article 13 of the American Convention on Human Rights provides:

1. Everyone has the right to freedom of thought and expression. This right includes freedom to seek, receive, and impart information and ideas of all kinds, regardless of frontiers, either orally, in writing, in print, in the form of art, or through any other medium of one’s choice.

2. The exercise of the right provided for in the foregoing paragraph shall not be subject to prior censorship but shall be subject to subsequent imposition of liability, which shall be expressly established by law to the extent necessary to ensure: respect for the rights or reputations of others; or the protection of national security, public order, or public health or morals.

3. The right of expression may not be restricted by indirect methods or means, such as the abuse of government or private controls over newsprint, radio broadcasting frequencies, or equipment used in the dissemination of information, or by any other means tending to impede the communication and circulation of ideas and opinions.

4. Notwithstanding the provisions of paragraph 2 above, public entertainments may be subject by law to prior censorship for the sole purpose of regulating access to them for the moral protection of childhood and adolescence.

5. Any propaganda for war and any advocacy of national, racial, or religious hatred that constitute incitements to lawless violence or to any other similar action against any person or group of persons on any grounds including those of race, color, religion, language, or national origin shall be considered as offenses punishable by law.

The African Charter on Human and People’s Rights, in Article 9, provides:

1. Every individual shall have the right to receive information.

2. Every individual shall have the right to express and disseminate his opinions within the law.

Article 10 of the European Convention on Human Rights provides:

1. Everyone has the right to freedom of expression. This right shall include freedom to hold opinions and to receive and impart information and ideas without interference by public authority and regardless of frontiers. This Article shall not prevent States from requiring the licensing of broadcasting, television or cinema enterprises.

2. The exercise of these freedoms, since it carries with it duties and responsibilities, may be subject to such formalities, conditions, restrictions or penalties as are prescribed by law and are necessary in a democratic society, in the interests of national security, territorial integrity or public safety, for the prevention of disorder or crime, for the protection of health or morals, for the protection of the reputation or rights of others, for preventing the disclosure of information received in confidence, or for maintaining the authority and impartiality of the judiciary.

The jurisprudence of the European Court of Human Rights offers the most extensive elucidation of the freedom of expression among regional and international courts and tribunals.