- A working definition. From the EUMC report 'Muslims in the European Union. Discrimination and Islamophobia' (2006):

"Islamophobia is a much used but little understood term. Although there is currently no legally agreed definition of Islamophobia, nor has social science developed a common definition, policy and action to combat it is undertaken within the broad concepts of racism and racial discrimination, which are universally accepted by Governments and international organisations. The EUMC therefore bases its approach to identifying the phenomenon and its manifestations on internationally agreed standards on racism and the ongoing work of the Council of Europe and
United Nations.

The Council of Europe’s European Commission against Racism and Intolerance (ECRI) General Policy Recommendation No. 8 on combating racism while fighting terrorism (ECRI (2004) 26): "As a result of the fight against terrorism engaged since the events of 11 September 2001, certain groups of persons, notably Arabs, Jews, Muslims, certain asylum seekers, refugees and immigrants, certain visible minorities and persons perceived as belonging to such groups, have become particularly vulnerable to racism and/or to racial discrimination across many fields of public life including education, employment, housing, access to goods and services, access to public places and freedom of movement".
ECRI General Policy Recommendation No. 5:  Muslim communities are subject to prejudice, which “may manifest itself in different guises, in particular through negative general attitudes but also to varying degrees, through discriminatory acts and through violence and harassment”. ECRI General Policy recommendation No. 7 defines racism as “the belief that a ground such as race, colour, language, religion, national or ethnic origin justifies contempt for a person or a group of persons, or the notion of superiority of a person or a group of persons”.

A distinction must also be made between attitudes and actions against Muslims based on unjust stereotypes and criticism of Muslim beliefs that can be seen as undermining fundamental rights. The common fundamental principles of the European Union and its Member States under Community law, the Charter of Fundamental Rights of the European Union and the European Convention for Protection of Human Rights and Fundamental Freedoms, must be respected."

- A Definition by the Runnymede Trust:
The Runnymede Trust has identified eight components that they say define Islamophobia.
This definition, from the 1997 document 'Islamophobia: A Challenge For Us All' is widely accepted, including by the European Monitoring Centre on Racism and Xenophobia.
The eight components are:

1) Islam is seen as a monolithic bloc, static and unresponsive to change.
2) Islam is seen as separate and 'other'. It does not have values in common with other cultures, is not affected by them and does not influence them.
3) Islam is seen as inferior to the West. It is seen as barbaric, irrational, primitive and sexist.
4) Islam is seen as violent, aggressive, threatening, supportive of terrorism and engaged in a 'clash of civilisations'.
5) Islam is seen as a political ideology and is used for political or military advantage.
6) Criticisms made of the West by Islam are rejected out of hand.
7) Hostility towards Islam is used to justify discriminatory practices towards Muslims and exclusion of Muslims from mainstream society.
8) Anti-Muslim hostility is seen as natural or normal.

- Institutional Islamophobia. From the Islamophobia. issues, challenges and action. A report by the Commission on British Muslims and  Islamophobia (2004):

"Producing inequalities

Institutional Islamophobia may be defined as those established laws, customs and practices which systematically reflect and produce inequalities in society between Muslims and non-Muslims. If such inequalities accrue to institutional laws, customs or practices, an institution is Islamophobic whether or not the individuals maintaining those practices have Islamophobic intentions. (Adapted from a statement by the Commission for Racial Equality.)

Inbuilt pervasiveness

Differential treatment need be neither conscious nor intentional, and it may be practised routinely by officers whose professionalism is exemplary in all other respects. There is great danger that focusing on overt acts of personal Islamophobia by individual officers may deflect attention from the much greater institutional challenge ... of addressing the more subtle and concealed form that organisational-level Islamophobia may take. Its most important challenging feature is its predominantly hidden character and its inbuilt pervasiveness within the occupational culture. (Adapted from a statement by Dr Robin Oakley)"